One-Pan Smoky Veggie Lentil Lasagne

There's something wonderfully liberating about lasagne that doesn't require a separate pot of boiling water and careful layering across multiple dishes. I discovered this one-pan approach on a particularly chaotic weeknight when my kitchen felt too small and my energy even smaller, yet I still wanted something warm and deeply satisfying. The magic happens right there in a single ovenproof skillet, where smoky lentils and roasted vegetables build into a sauce so rich you'd swear it simmered for hours. What started as a practical shortcut became my favorite way to make lasagne, because somehow cooking everything in one place makes the flavors feel more connected, more intentional.

I made this for a dinner party where someone unexpectedly arrived as a vegetarian guest, and instead of panicking, I felt relieved. By the time we pulled it from the oven, golden and bubbling at the edges, everyone was gathered in the kitchen breathing in that smoky, umami-forward aroma. Someone said it tasted like autumn in a pan, which isn't something you often hear about lasagne, but it stuck with me.

Ingredients

• Olive oil: Start with good quality here because it's one of the few fats carrying the whole show.
• Onion, garlic, carrots, celery, and red bell pepper: This is your flavor foundation, so don't rush the chopping or the cooking—those first ten minutes of sautéing are building the backbone.
• Mushrooms: Finely chopped, they become almost invisible but add an earthy umami that makes people wonder what makes this taste so complete.
• Courgette: Diced small so it softens into the sauce rather than staying as distinct chunks.
• Smoked paprika, oregano, thyme, and chili flakes: The smoked paprika is non-negotiable; it's the single ingredient that transforms this from ordinary to memorable.
• Canned tomatoes and tomato paste: Use whole peeled if you can find them, then crush them as you stir—it gives you control over texture.
• Red lentils: Rinse them thoroughly under cold water before using; this prevents a gummy texture later.
• Vegetable stock: Use warm stock if possible—it helps everything cook more evenly and gently.
• Balsamic vinegar: Added at the end, it brightens everything and adds a subtle sweetness that rounds out the smokiness.
• No-boil lasagne sheets: They actually work beautifully if your sauce is wet enough, which this one is.
• Ricotta, mozzarella, and Parmesan: Cold ricotta is easier to dollop, so take it from the fridge just before you need it.
• Fresh basil: Tear it by hand rather than cutting; it bruises less and stays bright green longer.

Instructions

Start your soffritto:

Heat olive oil in your largest ovenproof skillet over medium heat, then add finely chopped onion. Let it cook gently for about three to four minutes, stirring occasionally, until it turns translucent and sweet-smelling. You're not trying to brown it—just coax out its gentle flavor.

Build the vegetable layer:

Add minced garlic, diced carrots, celery, and red bell pepper all at once, stirring well to coat everything in oil. Cook for five minutes, watching as everything softens and begins to smell like the start of something good. The vegetables should still have a slight bite to them.

Add texture and depth:

Stir in finely chopped mushrooms and diced courgette, and let them cook for five to six minutes until they release their moisture and soften. You'll notice the pan will look wetter at first, then drier as that moisture evaporates—that's exactly right. Any mushroom flavor that seems to disappear is actually melting into the sauce.

Wake up the spices:

Sprinkle in smoked paprika, dried oregano, thyme, and chili flakes if you like heat. Stir constantly for about one minute until the spices bloom and smell fragrant and toasty. This short moment of heat brings every spice to life.

Build the sauce:

Pour in chopped tomatoes, stir in tomato paste, then add rinsed red lentils and warm vegetable stock. Season generously with salt and black pepper, tasting as you go. Bring everything to a gentle simmer, then cover the pan and cook for twenty to twenty-five minutes until the lentils are completely tender and the sauce is thick but still saucy.

Finish the bolognese:

Stir in balsamic vinegar, which will brighten everything and add subtle sweetness. Taste again and adjust seasoning if needed. Set your oven to 180°C (350°F).

Begin layering:

Remove roughly half the veggie bolognese from the pan and set it aside on a plate. This leaves a layer of sauce in the bottom of the pan as your foundation. Arrange lasagne sheets directly over this sauce, breaking them to fit if needed.

First cheese layer:

Dollop half your cold ricotta over the lasagne sheets in spoonfuls, then sprinkle with a third of the mozzarella and Parmesan combined. You don't need to spread the ricotta perfectly—it will soften and settle as things cook.

Add your reserved sauce:

Spread half the reserved veggie bolognese over the cheese layer in an even layer. Top with another set of lasagne sheets, breaking to fit.

Repeat the layers:

Dollop the remaining ricotta over these new sheets, sprinkle with another third of the cheese mixture, then spread the final reserved bolognese on top. Finish with your last layer of lasagne sheets, then scatter the remaining mozzarella and Parmesan across the top.

First bake:

Cover the entire pan tightly with foil and slide it into your preheated oven. Bake covered for twenty-five minutes, which keeps everything steaming gently and prevents the cheese from browning too quickly.

Final bake:

Remove the foil and bake for another ten to fifteen minutes until the top is golden brown and bubbling at the edges. Watch it in the final minutes so it browns without burning.

Rest and serve:

Remove from the oven and let it sit undisturbed for ten minutes—this gives everything time to set slightly so you can cut clean portions. Tear fresh basil leaves and scatter them over the top just before serving.

Save

What I remember most isn't actually eating this lasagne but the moment my skeptical friend took a second bite and said, quietly, that he'd been wrong about vegetarian cooking all along. We sat there in the kitchen afterward, the pan still warm, talking about how food can shift our assumptions so simply, and I realized that's when a recipe becomes more than instructions on a page.

Why This Works as a One-Pan Meal

Cooking lasagne in a single ovenproof skillet works because you're not trying to separate steps—you're letting them flow into each other naturally. The bolognese stays hot while you layer, the moisture in the sauce keeps the no-boil sheets from drying out, and everything finishes together at the same moment. This isn't a compromise or a shortcut that sacrifices flavor; it's actually a smarter way to build a lasagne because the vegetables, spices, and lentils have time to become one unified sauce before anything hits the oven.

Adjusting for Your Preferences

If you want extra smokiness, add a tiny pinch of liquid smoke after the balsamic vinegar—just a quarter teaspoon at first, then taste and adjust, because it's easy to overdo. For a spicier version, increase the chili flakes to three-quarters of a teaspoon or add fresh sliced chili alongside the garlic. If mushrooms aren't your thing, replace them with finely chopped walnuts sautéed until toasted, which adds a similar earthiness and texture.

Serving and Storing

This lasagne tastes even better the next day once the flavors have settled into each other, so don't hesitate to make it ahead. Serve it with a simple green salad dressed in lemon vinaigrette to cut through the richness, and thick slices of crusty bread for soaking up every bit of sauce. Leftovers keep in the refrigerator for four days and reheat beautifully covered with foil at 160°C for about fifteen minutes.

• A light Italian red wine like Chianti or Valpolicella pairs beautifully without overpowering the vegetables.
• For a vegan version, swap ricotta and mozzarella for cashew ricotta and plant-based mozzarella, and use nutritional yeast instead of Parmesan.
• If you're feeding a crowd, this recipe doubles easily—just use a larger pan or split the mixture between two skillets.

Save

There's something grounding about a lasagne that comes from one pan, made without fuss but tasting like you spent all day thinking about it. I hope this becomes one of those meals you turn to when you want something that feels both nourishing and special.

Recipe Questions & Answers

→ Can I make this gluten-free?

Yes, simply substitute the regular lasagne sheets with gluten-free oven-ready sheets. The cooking time remains the same.

→ What can I use instead of ricotta?

Cottage cheese blended until smooth works well, or try a vegan ricotta alternative for a dairy-free version.

→ How long does this keep in the refrigerator?

Stored in an airtight container, it keeps well for 3–4 days. Reheat individual portions in the microwave or cover the whole pan with foil and warm in the oven.

→ Can I freeze this lasagne?

Absolutely. Assemble the entire dish, wrap tightly in foil and freeze before baking. Thaw overnight in the refrigerator then bake as directed, adding 5–10 minutes to the covered baking time.

→ Do I need to cook the lasagne sheets first?

No, use oven-ready no-boil sheets which soften as they bake in the saucy vegetable mixture. This creates perfectly tender layers without extra prep work.

→ Can I add other vegetables?

Spinach, chopped eggplant, or diced butternut squash all work beautifully. Just keep the total vegetable quantity similar so the sauce consistency remains right.