Veggie Pesto & Spinach Lasagna

Comfort food that feels like a warm, satisfying hug—this Veggie Pesto & Spinach Lasagna blends a silky white sauce with bright basil pesto and a verdant spinach filling. It’s an easy weeknight dinner that doubles as a stunning dish for company. Layers of tender lasagna sheets, a creamy beurre-blanc-style sauce, basil-rich pesto, and plenty of cheese make each forkful comforting and balanced. Below you’ll find an ingredient list followed by clear, step-by-step directions, tips for success, and helpful serving and storage notes.

Why you’ll love this recipe

This Veggie Pesto & Spinach Lasagna is indulgent without being heavy. The white sauce gives the dish a smooth, velvety base so the pesto and spinach can sing. It’s straightforward to assemble and bakes into a bubbling, golden-topped casserole that slices beautifully. If you like the fresh brightness of pesto with the richness of a cheesy lasagna, this is a keeper.

Ingredients

• 1 large onion, finely chopped
• 600 g spinach, coarsely chopped
• 100 g butter
• 100 g flour
• 1 l whole milk
• 300 g basil pesto
• 100 g parmesan + extra for sprinkling
• 1 packet of lasagna sheets
• salt
• pepper
• olive oil

Equipment

• Large frying pan or sauté pan
• Medium saucepan
• Whisk
• Stirring spoon
• Baking dish (approx. 23 x 33 cm / 9 x 13 in or similar)
• Aluminum foil

Prep work (15–20 minutes)

Preheat your oven to 180°C (350°F). Finely chop the onion and coarsely chop the spinach. Grate the parmesan if it’s not pre-grated. Have the lasagna sheets and pesto ready to go. A little prep makes assembly quick and calm.

Step-by-step directions

Follow these rewritten steps to go from raw ingredients to a bubbling pan of Veggie Pesto & Spinach Lasagna. The steps are ordered to match the recipe flow and keep things simple and efficient.

1. Sauté the onion: Heat a drizzle of olive oil in a large frying pan over medium heat. Add the finely chopped onion and cook, stirring occasionally, until it becomes translucent and soft, about 6–8 minutes. Season lightly with a pinch of salt and a few grinds of black pepper.
2. Wilt the spinach: Add the coarsely chopped spinach to the pan with the softened onion. Toss and cook until the spinach has fully wilted and most of its moisture has evaporated, about 3–5 minutes. Remove from heat and set aside while you make the white sauce.
3. Make the white sauce (béchamel-style): In a medium saucepan, melt 100 g butter over medium heat. Once melted and foamy, sprinkle in the 100 g flour and whisk constantly to form a roux. Cook the roux for 1–2 minutes, whisking, to remove the raw flour taste but do not let it brown.
4. Gradually add the milk: Slowly pour in the 1 l whole milk while whisking continuously to prevent lumps. Keep the heat at medium and whisk until the mixture thickens to a smooth, coat-the-spoon consistency—about 6–8 minutes. Taste and season with salt and pepper. Remove from heat.
5. Stir in pesto and parmesan: While the white sauce is still warm, whisk in 300 g basil pesto until fully incorporated and the sauce turns a pale green. Add 100 g parmesan and whisk until melted and the sauce is smooth. This pesto-parmesan béchamel will be the main flavor bridge in the lasagna.
6. Combine onion and spinach with a little sauce: Fold the wilted spinach and cooked onion into a small portion of the sauce (reserve about a cup of sauce for layering), ensuring the vegetable mixture is well coated. This distributes flavor and keeps the layers from drying out.
7. Assemble the lasagna: Lightly oil the bottom and sides of your baking dish with a little olive oil. Spoon a thin layer of the pesto béchamel across the bottom of the dish to prevent sticking. Lay down the first layer of lasagna sheets to cover the base—trim sheets if needed to fit.
8. Layering: Spread a portion of the spinach-onion mixture over the lasagna sheets, followed by a generous drizzle of the pesto béchamel. Sprinkle a little of the 100 g parmesan over the sauce. Repeat: lasagna sheets, spinach-onion, sauce, parmesan, building up 3–4 layers depending on the depth of your dish and the number of sheets in the packet. Finish with a top layer of lasagna sheets, a generous final pour of the remaining pesto béchamel, and a final sprinkle of extra parmesan for browning.
9. Cover and bake: Cover the baking dish tightly with aluminum foil and place it in the preheated oven. Bake covered for 20 minutes. This steams the pasta and warms the fillings through.
10. Bake uncovered to brown: After 20 minutes, remove the foil and continue baking for another 15–20 minutes until the top is bubbling and the cheese is lightly golden. Keep an eye on it so the top doesn’t over-brown.
11. Rest before serving: Remove the lasagna from the oven and let it rest for 10–15 minutes before slicing. Resting helps the layers set so you can cut neat squares.

Tips for success

• If your pesto is very thick, stir in a tablespoon of olive oil or a splash of milk to loosen it before adding to the white sauce so it blends smoothly.
• Shake excess water from the spinach after chopping and wilting; too much moisture can make the lasagna watery. If the spinach still seems wet, return it to the pan for another minute to evaporate extra liquid.
• When layering, use just enough béchamel to cover the sheets—too much will make the lasagna heavy, too little will risk dryness. The reserved cup of sauce is handy for adjusting as you go.
• Pre-cooked or no-boil lasagna sheets work well. If using regular dried sheets, ensure your sauce is plentiful so the pasta hydrates fully in the oven. If you have fresh pasta sheets, you may need slightly less sauce on each layer.
• Letting the lasagna rest is crucial. It may be tempting to dig in hot from the oven, but resting yields cleaner slices and better texture.

Serving suggestions

Serve your Veggie Pesto & Spinach Lasagna with a crisp green salad dressed simply with lemon, olive oil, salt, and pepper. Crusty bread or garlic bread makes a comforting side, and a light, acidic wine or sparkling water complements the richness of the pesto-béchamel.

Storage and reheating

• Refrigerate leftovers in an airtight container for up to 3 days. To reheat, place a portion in a small ovenproof dish, cover with foil, and bake at 160°C (320°F) until warmed through, about 20–25 minutes. You can also microwave single portions until heated, stirring halfway for even warmth.
• To freeze, wrap cooled lasagna tightly in foil and place in a freezer bag. Freeze for up to 2 months. Thaw overnight in the fridge before reheating in the oven as above.

Ingredient notes and swaps

• Spinach: Baby or mature spinach can be used. If you prefer, swap in mixed greens (kale or chard) but adjust the wilting time—tougher greens need a minute or two longer to soften.
• Basil pesto: Use store-bought for speed or homemade pesto if you have fresh basil, pine nuts (or toasted walnuts/almonds), olive oil, garlic, and parmesan. Taste the pesto first—if it’s already salty, reduce added salt to the sauce.
• Parmesan: A finely grated hard cheese of similar texture and saltiness works here. Add the extra parmesan for the golden finish.
• Lasagna sheets: No-boil or oven-ready sheets are the most convenient. If you’re using standard dried sheets, ensure the béchamel is plentiful so they cook fully in the oven.

Make-ahead and entertaining

This Veggie Pesto & Spinach Lasagna is an excellent make-ahead dish. Assemble it, cover, and refrigerate for up to 24 hours. When you’re ready to serve, remove from the fridge while the oven preheats and bake as directed, adding a few extra minutes if still cold from the fridge. For dinner parties, prepare it a day ahead to save time—baked and reheated lasagna actually benefits from the flavors mingling overnight.

Frequently asked questions

Can I add other vegetables? Yes. Roasted courgette, mushrooms, or thinly sliced roasted peppers would all fit well. Sauté any additional vegetables first to reduce moisture and concentrate flavor before layering.

Is this suitable for a make-ahead freezer meal? Yes. Freeze fully assembled (unbaked or baked) in a tightly wrapped container and thaw before baking if frozen unbaked. If baking from frozen, allow extra oven time and keep it covered until the center is hot.

How can I make it lighter? Use a lower-fat milk or reduce the butter in the béchamel slightly. Keep in mind that the sauce texture and richness will change with lower-fat dairy.

Final thoughts

This Veggie Pesto & Spinach Lasagna strikes a lovely balance: the herbaceous pesto brightens a rich, creamy sauce; the spinach and onion add structure and freshness; and the parmesan brings savory depth. It’s a crowd-pleasing vegetarian main that feels special enough for guests yet easy enough for a cozy family dinner. Try it once—you’ll likely find it on rotation for weeknights and weekends alike.

Enjoy your lasagna. Let it rest, slice with confidence, and savor each layered bite.