Cook lasagna noodles in boiling salted water until al dente, then drain.
3
In a large skillet, heat olive oil over medium heat.
4
Sauté zucchini, eggplant, and bell pepper until tender, about 5-7 minutes.
5
In a bowl, mix ricotta cheese with oregano, salt, and pepper.
6
Spread a thin layer of marinara sauce in a baking dish.
7
Place 3 noodles over the sauce.
8
Layer half of the sautéed vegetables, spread half of the ricotta mixture, add a layer of mozzarella, then repeat with remaining noodles, vegetables, ricotta, and mozzarella.
9
Top with remaining marinara sauce and mozzarella cheese.
10
Cover with aluminum foil and bake for 40 minutes.
11
Remove foil and bake for an additional 10 minutes until cheese is bubbly and golden.