This delicious vegetable lasagna is a hearty, flavor-packed recipe that is ideal for keeping on hand to impress guests or preparing a veg-packed dinner. I've made this version countless times, especially when cooking for a crowd or meal prepping for the week, because it slices beautifully, reheats well, and feels just as satisfying as a classic lasagna.

Roasting the vegetables first is the key step here. It concentrates their flavor, removes excess moisture (which helps avoid a watery lasagna), and gives the whole dish a deeper, richer taste. Yes, it's a few extra steps, but every one of them is worth it.

If you like this style of veggie-forward comfort food, you might also enjoy this lighter zucchini lasagna, eggplant parmigiana, this showstopping baked tortellini lasagna, or a creamy gnocchi bake. They all hit that same cozy, oven-baked sweet spot.

Ingredient Notes

The exact quantities are in the recipe card, but here's why these ingredients work so well and where you can make swaps.

• Zucchini & eggplant - These form the bulk of the vegetable layer. Roasting them first removes excess moisture, which is crucial for structure. Don't skip this step - I've tested it without roasting, and the lasagna turns soupy and has a much less intense, delicious flavor.
  
• Bell peppers & mushrooms - Add sweetness and umami. Mushrooms especially help give the lasagna a more savory, meaty depth without any actual meat.
  
• Spinach - Stirred in at the end so it wilts without releasing too much water. Frozen spinach works too - just squeeze it very dry.
  
• Passata with basil - Keeps the sauce simple but flavorful. If using plain passata, add extra dried basil.
  
• Red pepper flakes - Optional, but I highly recommend a small pinch for balance.
  
• Bechamel sauce - This creamy layer ties everything together. Using cheddar here adds a bit more sharpness than traditional Parmesan-only béchamel, which I really like in veggie-heavy lasagnas.
  
• Lasagna sheets - I use dried lasagna sheets (just make sure you add enough sauce to coat them and cook the lasagna for long enough! You could use fresh lasagna sheets, but you may need to adjust the cooking times.
  
• Mozzarella + cheddar topping - Mozzarella gives stretch and melty goodness, whilst cheddar gives flavor. You can swap mozzarella for vegetarian Parmesan if preferred.

How to Make This Gorgeous Roasted Vegetable Lasagna

Step 1) Roast the vegetables

Dice your zucchini, eggplant, peppers, and mushrooms into evenly-sized cubes.  Then, toss with olive oil, Italian seasoning, salt, and pepper. Roast at 220C (428F) for 30 minutes, then add the minced garlic and roast 10 minutes more. Stir in spinach at the end - the heat of the vegetables will wilt it down without any extra heat needed.

Step 2) Make the Sauces

To make the tomato sauce: Sauté onion, carrot, and celery in oil for 5-6 minutes, then add the passata, herbs, red pepper flakes, and water. Simmer the sauce for at least 30 minutes (I do this while the vegetables are roasting in the oven!) until thick. We want to avoid adding anything too watery to the lasagna to get those lovely thick layers.

To make the béchamel: Melt butter, whisk in flour, then slowly whisk in milk until smooth. Cook until thickened, then remove from the heat and stir in cheese and black pepper.

Step 3) Assemble the Lasagna

To assemble your lasagna, first spread a thin layer of the tomato sauce over the bottom of your baking dish. Then, add the lasagna noodles (I usually overlap two sheets, but this will depend on the size of your dish), then a layer of béchamel, roasted vegetables, cheese, and tomato sauce again. Repeat until you finish with the noodles, then sauce, béchamel, and cheese on top.

It doesn't matter too much what component goes where - just aim for at least three layers of lasagna noodles, and to finish with the sauce, then the bechamel, then the cheese for that perfect melty, golden topping.

Step 4) Cook your Lasagna

Bake at 200C (400F) for 35-40 minutes until golden and bubbling. Important! Let your lasagna sit for at least 10-15 minutes before slicing and serving - this lets it "settle" and will ensure you get those lovely layers in your lasagna servings.

Chef's Tips / Cooking Hacks

• Aim to roast your vegetables until they're lightly caramelized and beginning to crisp on the edges - pale vegetables = bland lasagna.
  
• If your roasted veg releases liquid, drain them briefly in a colander before layering. We want to remove as much excess liquid as possible to avoid a watery lasagna.
  
• Letting the lasagna rest is non-negotiable if you want clean slices. 10 minutes minimum, but ideally 20 minutes (cover the top with foil and you'll lose minimal heat!).
  
• This is even better the next day, once the flavors settle! I love prepping a big tray of this vegetable lasagna and freezing individual portions for the next couple of weeks.

Storage

• Store leftovers in an airtight container in the fridge for up to 4 days.
• Freeze fully cooked portions for up to 3 months. Defrost overnight in the fridge.
• Reheat covered in the oven or microwave until piping hot.

FAQs

Can I make this ahead of time?
Yes - assemble fully, refrigerate up to 24 hours, then bake when ready.

Can I make it vegan?
Yes. Use plant-based milk and butter for the béchamel and vegan cheese alternatives.

Why roast the vegetables instead of cooking them in the sauce?
Roasting removes moisture and intensifies flavor, which keeps the lasagna rich instead of watery.

This Vegetable lasagna is hearty, packed with flavor, and makes the perfect meal-prep dish. It's a fantastic way to enjoy a comforting, layered pasta bake while sneaking in a ton of vegetables. 

Whether you serve it fresh from the oven or enjoy the leftovers the next day, it's guaranteed to be a hit. Let me know if you try it-I'd love to hear how it turns out!