Green Lentil and Vegetable Casserole

Featured in: Hearty Dinners

This wholesome casserole brings together tender green lentils and a colorful medley of vegetables including carrots, zucchini, bell peppers, and mushrooms. The vegetables are sautéed with aromatic herbs like thyme and oregano, then combined with the lentils and baked until bubbly with a golden Parmesan crust. Perfect for meal prep, this dish serves four and can easily be adapted with whatever seasonal vegetables you have on hand.

Updated on Wed, 21 Jan 2026 15:33:00 GMT
Golden-brown Green Lentil and Vegetable Casserole fresh from the oven, bubbling with carrots, zucchini, and spinach in a savory herb-infused sauce. Save It
Golden-brown Green Lentil and Vegetable Casserole fresh from the oven, bubbling with carrots, zucchini, and spinach in a savory herb-infused sauce. | sunnyspoonful.com

The first time I made this casserole was during a particularly brutal February when my apartment radiator kept making these mysterious banging sounds. I needed something that would fill the whole space with warmth and smell like comfort itself. The lentils were an impulse buy from the bulk aisle, and I honestly just started throwing in whatever vegetables were wilting in my crisper drawer. Now it is the dinner I make when I need to feel like everything is going to be okay.

Last winter my friend Sarah came over after a terrible day at work, and I just happened to have a batch of this in the oven. She took one bite of that crispy Parmesan topping and actually started crying, not from sadness but because sometimes food just hits you right when you need it most. We sat at my kitchen table for two hours picking at the casserole and talking about nothing and everything at the same time.

Ingredients

  • 1 cup dried green lentils, rinsed: These hold their shape beautifully and provide a earthy, nutty base that really anchors the whole dish
  • 3 cups vegetable broth: Use a good quality broth here because it is going to be absorbed by the lentils and become part of the flavor foundation
  • 1 medium onion, diced: I like yellow onions for their sweetness that develops as they cook down
  • 2 cloves garlic, minced: Do not be shy with the garlic, it mellows out beautifully in the oven
  • 2 medium carrots, sliced: These add a lovely natural sweetness and a bit of crunch even after baking
  • 1 medium zucchini, diced: Choose a firm one with no soft spots, as it will release some moisture during baking
  • 1 red bell pepper, diced: The red bell pepper brings this gorgeous color and a subtle fruity sweetness
  • 1 cup button mushrooms, sliced: They become meaty and umami rich as they roast in the casserole
  • 1 cup cherry tomatoes, halved: These burst slightly in the oven and create these little pockets of juicy brightness
  • 2 cups fresh spinach, roughly chopped: It might seem like a lot but it wilts down dramatically and adds such a lovely fresh element
  • 2 tbsp olive oil: This helps all the vegetables roast and caramelize beautifully
  • 1 tsp dried thyme: Thyme has this way of making everything taste cozy and home cooked
  • 1 tsp dried oregano: Brings that classic herbal warmth that pairs so well with lentils
  • 1/2 tsp smoked paprika: This is the secret ingredient that adds such a wonderful depth and subtle smokiness
  • 1/2 tsp ground black pepper: Freshly cracked makes all the difference here
  • 1/2 tsp salt: Start with this and adjust to your taste later
  • 1/3 cup grated Parmesan cheese: Creates this incredible golden, salty crust on top that everyone fights over
  • 1/2 cup gluten-free breadcrumbs: These add such a satisfying crunch to the topping, but you can leave them out if you prefer

Instructions

Product image
Easily spray or drizzle oil for roasting vegetables, air frying, sautéing, and dressing salads with controlled coverage.
Check price on Amazon
Get the lentils started:
Preheat your oven to 375°F and get that kitchen warming up. In a medium saucepan, combine the rinsed lentils with your vegetable broth and bring it all to a bubbly boil before reducing the heat to let them simmer gently.
Simmer the lentils:
Cook those lentils uncovered for about 20 to 25 minutes until they are tender but still have a nice bite to them. Drain any excess liquid because nobody wants a soupy casserole.
Sauté the aromatics:
While the lentils are doing their thing, heat your olive oil in a large skillet over medium heat. Toss in your diced onion and minced garlic, letting them cook for about 2 to 3 minutes until your kitchen starts smelling amazing and the onions turn translucent.
Add the hearty vegetables:
Throw in the carrots, zucchini, red bell pepper, and those sliced mushrooms. Stir everything around and let it cook for another 5 to 7 minutes until the veggies start to soften and look inviting.
Season and add the delicate vegetables:
Stir in the cherry tomatoes, spinach, thyme, oregano, smoked paprika, salt, and pepper. Let everything cook together for just 2 to 3 more minutes until that spinach wilts down and looks perfectly cozy.
Combine everything:
In a large mixing bowl, dump in those cooked lentils and all your beautiful sautéed vegetables. Give it all a good mix until the lentils and vegetables are evenly distributed throughout.
Assemble the casserole:
Transfer the whole mixture to a greased 2 quart baking dish and spread it out evenly. Sprinkle that Parmesan cheese and the breadcrumbs over the top like you are tucking it in for a nice long nap.
Bake to golden perfection:
Pop the dish in the oven and bake it uncovered for 20 to 25 minutes. You want the top to get golden and crispy and the whole thing to be bubbling around the edges.
Let it rest:
This is the hardest part but give the casserole about 5 minutes to rest before serving. It lets everything settle and makes serving so much easier.
Product image
Easily spray or drizzle oil for roasting vegetables, air frying, sautéing, and dressing salads with controlled coverage.
Check price on Amazon
Hearty Green Lentil and Vegetable Casserole served in a rustic baking dish, topped with melted cheese and fresh herbs for a comforting vegetarian meal. Save It
Hearty Green Lentil and Vegetable Casserole served in a rustic baking dish, topped with melted cheese and fresh herbs for a comforting vegetarian meal. | sunnyspoonful.com

This recipe became my go to for new neighbors and stressed out friends because there is something about a bubbling casserole that says welcome home better than words ever could. My mom now calls me every time she makes it, reporting back on whatever vegetables she substituted and how it was still perfect.

Making It Your Own

The beauty of this casserole is how forgiving it is with substitutions. I have made it with butternut squash in the fall and asparagus in the spring, and each variation feels like discovering the recipe all over again. Just keep the total vegetable amount roughly the same and you really cannot go wrong.

The Topping Secret

That Parmesan and breadcrumb topping is what transforms this from a simple lentil dish into something that feels special enough for Sunday dinner. Sometimes I mix a little garlic powder into the breadcrumbs, or add some extra smoked paprika if I am feeling adventurous.

Serving Suggestions

This casserole is substantial enough to stand alone as a main, but it pairs beautifully with simple sides that do not compete with its hearty flavors. A light green salad with a bright vinaigrette cuts through the richness perfectly.

  • Crusty gluten free bread is perfect for soaking up any juices
  • A dollop of Greek yogurt or sour cream on top adds a lovely tang
  • Leftovers reheat beautifully for next day lunches
Product image
Toast bread, bagels, and sourdough evenly for breakfast, sandwiches, and quick meal prep.
Check price on Amazon
A slice of Green Lentil and Vegetable Casserole on a white plate, revealing layers of tender lentils and colorful vegetables, paired with a crisp side salad. Save It
A slice of Green Lentil and Vegetable Casserole on a white plate, revealing layers of tender lentils and colorful vegetables, paired with a crisp side salad. | sunnyspoonful.com

There is something deeply satisfying about serving a dish that looks impressive but comes together with such humble ingredients. I hope this casserole becomes a comfort in your kitchen too.

Recipe FAQs

Can I make this casserole ahead of time?

Yes, you can assemble the entire casserole up to 24 hours in advance and store it covered in the refrigerator. Bake when ready to serve, adding an extra 5-10 minutes if baking cold from the fridge.

What vegetables work best in this dish?

Root vegetables like sweet potatoes, squash, or parsnips work wonderfully. You can also add kale, Swiss chard, or green beans. The beauty of this casserole is its versatility with seasonal produce.

How do I store leftovers?

Store leftover portions in an airtight container in the refrigerator for up to 4 days. Reheat in the microwave or cover with foil and warm in a 350°F oven until heated through.

Can I freeze this casserole?

Yes, freeze the unbaked or baked casserole for up to 3 months. Wrap tightly with plastic wrap and foil. Thaw overnight in the refrigerator before baking or reheating.

Is this suitable for meal prep?

Absolutely. This casserole freezes well and portioned containers make excellent grab-and-go lunches throughout the week. The flavors actually improve after a day or two in the refrigerator.

What can I serve with this casserole?

A simple green salad with vinaigrette balances the hearty casserole beautifully. Crusty gluten-free bread or roasted potatoes also make excellent sides. For a complete meal, pair with a light red wine like Pinot Noir.

Green Lentil and Vegetable Casserole

Comforting baked dish with lentils, vegetables, and herbs topped with golden Parmesan.

Prep Time
20 mins
Cook Time
50 mins
Total Duration
70 mins
Authored by Lana Bright

Recipe Type Hearty Dinners

Skill Level Easy

Cuisine Style International

Recipe Yield 4 Serving Size

Diet Preferences Vegetarian-Friendly, Free From Gluten

What You'll Need

Lentils

01 1 cup dried green lentils, rinsed
02 3 cups vegetable broth

Vegetables

01 1 medium onion, diced
02 2 cloves garlic, minced
03 2 medium carrots, sliced
04 1 medium zucchini, diced
05 1 red bell pepper, diced
06 1 cup button mushrooms, sliced
07 1 cup cherry tomatoes, halved
08 2 cups fresh spinach, roughly chopped

Herbs & Seasonings

01 2 tbsp olive oil
02 1 tsp dried thyme
03 1 tsp dried oregano
04 1/2 tsp smoked paprika
05 1/2 tsp ground black pepper
06 1/2 tsp salt

Topping

01 1/3 cup grated Parmesan cheese
02 1/2 cup gluten-free breadcrumbs

Directions

Step 01

Preheat Oven: Preheat the oven to 375°F.

Step 02

Cook Lentils: Combine lentils and vegetable broth in a medium saucepan. Bring to a boil, reduce heat, and simmer uncovered for 20–25 minutes until lentils are tender but not mushy. Drain any excess liquid.

Step 03

Sauté Aromatics: Heat olive oil in a large skillet over medium heat. Sauté onion and garlic for 2–3 minutes until fragrant.

Step 04

Cook Vegetables: Add carrots, zucchini, bell pepper, and mushrooms. Cook, stirring occasionally, for 5–7 minutes until vegetables begin to soften.

Step 05

Add Seasonings and Greens: Stir in cherry tomatoes, spinach, thyme, oregano, smoked paprika, salt, and black pepper. Cook for another 2–3 minutes until spinach wilts.

Step 06

Combine Filling: Combine cooked lentils and sautéed vegetables in a large mixing bowl. Mix well to incorporate.

Step 07

Assemble Casserole: Transfer the mixture to a greased 2-quart baking dish. Sprinkle with Parmesan cheese and breadcrumbs.

Step 08

Bake: Bake uncovered for 20–25 minutes, until the top is golden and the casserole is bubbling.

Step 09

Rest and Serve: Let rest for 5 minutes before serving.

Tools You'll Need

  • Medium saucepan
  • Large skillet
  • Mixing bowl
  • 2-quart baking dish
  • Chef's knife
  • Cutting board

Allergy Information

Review each ingredient to identify potential allergens, and consult a healthcare professional if you're unsure.
  • Contains milk (Parmesan cheese)
  • May contain gluten (breadcrumbs)

Nutrition Details (Per Serving)

This nutritional data is for reference only and isn't a substitute for medical advice.
  • Caloric Value: 320
  • Fats: 8 grams
  • Carbohydrates: 48 grams
  • Proteins: 16 grams