01 -
Preheat the oven to 400°F (200°C).
02 -
Toss the red bell pepper, yellow squash, zucchini, and carrots with olive oil, salt, and pepper. Spread evenly on a large baking sheet and roast for 20 minutes, stirring halfway through. Remove from oven and set aside.
03 -
In a mixing bowl, combine ricotta cheese, egg, half of the Parmesan, dried oregano, a pinch of salt, and pepper. Stir until smooth and well blended.
04 -
Lightly grease a 9x13-inch baking dish.
05 -
Spread 1/2 cup of tomato sauce onto the bottom of the baking dish. Arrange 4 sheets of no-boil lasagna noodles on top.
06 -
Top the noodles with a layer of roasted red bell peppers and yellow squash. Spoon one third of the ricotta mixture over the vegetables, scatter a portion of spinach leaves, and drizzle one third of the béchamel sauce on top.
07 -
Place 4 more lasagna noodles over the previous layer. Ladle over tomato sauce, then add roasted zucchini and carrots. Spread with another third of the ricotta mixture, add more spinach, and another portion of béchamel.
08 -
Arrange the final 4 noodles. Spoon over the remaining tomato sauce, last portion of ricotta mixture, more spinach, and finish with the remaining béchamel.
09 -
Sprinkle shredded mozzarella and the remaining Parmesan evenly over the top layer.
10 -
Cover the dish tightly with aluminum foil and bake for 30 minutes.
11 -
Remove the foil and bake for 15 to 20 additional minutes until the top is golden and bubbling.
12 -
Let the lasagna rest for at least 10 minutes before slicing and serving.