Roasted Vegetable Lasagna White Sauce

The first time I made this lasagna, my kitchen filled with the most incredible smell of roasted vegetables and bubbling cheese. My roommate wandered in from her room, drawn by the aroma, and asked what restaurant I had ordered from. When I told her it was homemade, she grabbed a fork and stood by the counter until it came out of the oven.

I first attempted this on a rainy Sunday when I needed something cozy but wanted to avoid the usual heavy meat sauce. The vegetables caramelize in the oven, concentrating their flavors in a way that makes every layer distinctive. Even my vegetable-skeptical brother went back for seconds without any prompting from me.

Ingredients

• Large zucchini and eggplant: Slice them about 1/4 inch thick so they roast evenly but still hold their texture in the layers
• Bell peppers and red onion: These add sweetness and color that make the lasagna look as good as it tastes
• Olive oil and oregano: Coat the vegetables thoroughly before roasting to get those nice caramelized edges
• Unsalted butter and flour: The base of your roux, keep the heat medium so your butter does not brown too quickly
• Whole milk: Warm it up before adding to prevent lumps from forming in your white sauce
• Nutmeg and white pepper: These are the secret ingredients that make béchamel taste like something from a nice restaurant
• No-boil lasagna noodles: They absorb excess moisture from the vegetables and sauce as they bake
• Mozzarella and Parmesan: The combination gives you that perfect stretchy top and salty finish

Instructions

Roast the vegetables:

Preheat your oven to 425°F and line a baking sheet with parchment paper for easy cleanup. Arrange your zucchini, eggplant, peppers, and onion in a single layer, drizzle with olive oil, and sprinkle with oregano, salt, and pepper. Roast for 20 to 25 minutes, stirring halfway through, until everything is tender and starting to brown in spots. Lower your oven temperature to 375°F when the vegetables are done.

Make the white sauce:

Melt the butter in a medium saucepan over medium heat, then whisk in the flour and cook for about 2 minutes until it bubbles but stays pale. Slowly pour in the warm milk while whisking constantly, keep stirring for 5 to 7 minutes until the sauce thickens enough to coat the back of a spoon. Stir in the salt, nutmeg, white pepper, and Parmesan, then remove it from the heat.

Build your layers:

Spread a thin layer of white sauce on the bottom of your 9x13-inch baking dish so the noodles do not stick. Place 3 noodles, top with a third of the roasted vegetables, a quarter of the white sauce, and a third of the mozzarella. Repeat this two more times, then finish with the remaining white sauce, mozzarella, and the extra Parmesan on top.

Bake until golden:

Cover the dish with foil and bake at 375°F for 30 minutes, then remove the foil and bake another 15 to 20 minutes until the cheese is bubbly and golden brown. Let it rest for 10 minutes before cutting into squares so the layers set up and do not slide apart when you serve it.

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This recipe became my go-to for new neighbors and friends who need a comforting meal. Something about the layers of creamy sauce and sweet roasted vegetables makes people feel taken care of, which is really what cooking is all about.

Make Ahead Magic

You can assemble the entire lasagna up to a day ahead, cover it tightly, and refrigerate until you are ready to bake. Add about 10 minutes to the covered baking time if it goes into the oven cold from the refrigerator.

Vegetable Variations

Swap in whatever vegetables look good at the market or need using up from your crisper drawer. Mushrooms, sliced squash, or even blanched broccoli work beautifully as long as you roast or cook them first so they do not release too much water.

Serving Suggestions

A crisp green salad with a bright vinaigrette cuts through the richness of the white sauce. Crusty bread is nice for sopping up any extra sauce, and a light white wine like Pinot Grigio complements the roasted vegetables perfectly.

• Let the lasagna rest the full 10 minutes, I know it smells amazing but patience pays off here
• Cut squares with a sharp knife and use a spatula to keep layers intact
• Store leftovers in the refrigerator and they reheat beautifully in the microwave

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There is something so satisfying about pulling a bubbling lasagna out of the oven and watching people gather around the counter. Hope this becomes one of those recipes you turn to again and again.

Recipe Questions & Answers

→ Can I prepare this lasagna ahead of time?

Absolutely. You can assemble the entire lasagna up to 24 hours before baking, cover tightly, and refrigerate. Add 5-10 minutes to the covered baking time if baking cold. You can also freeze the assembled, unbaked lasagna for up to 3 months—thaw overnight in the refrigerator before baking.

→ What vegetables work best for roasting in this lasagna?

Zucchini, eggplant, and bell peppers are ideal because they hold their texture during roasting and layering. You can also add sliced mushrooms, spinach, or even butternut squash. Just avoid vegetables with high water content like tomatoes unless they're well-drained after roasting.

→ Is it necessary to use no-boil noodles?

No-boil noodles work perfectly here because they absorb moisture from the vegetables and sauce while baking. If using regular lasagna noodles, boil them according to package directions until al dente, then drain and rinse with cold water before layering. The assembly process remains the same.

→ Can I make the white sauce ahead of time?

Yes, you can prepare the béchamel up to 2 days in advance. Cool it completely, cover tightly, and refrigerate. When ready to use, gently reheat while whisking to smooth out any lumps. Thin with a splash of warm milk if it has thickened too much during storage.

→ How do I know when the lasagna is perfectly done?

The lasagna is ready when the cheese is golden and bubbling, and you can see the sauce actively bubbling around the edges. The top should be lightly browned. Letting it rest for 10 minutes before slicing is crucial—this allows the layers to set so you get clean, neat portions.

→ What can I serve with this lasagna?

A crisp green salad with vinaigrette cuts through the richness beautifully. Crusty garlic bread or focaccia is perfect for soaking up extra sauce. For wine, try a Pinot Grigio or Sauvignon Blanc—the acidity balances the creamy white sauce nicely.