-
1
Bring a large pot of lightly salted water to a boil. Stir in lasagna noodles and return to a boil. Cook the pasta uncovered, stirring occasionally, until the noodles have cooked through but are still firm to the bite, about 8 minutes. Drain and set aside.
-
2
Preheat oven to 350 degrees F (175 degrees C).
-
3
Spray a 9x13-inch baking dish with cooking spray.
-
4
Heat olive oil in a large skillet over medium-high heat. Cook and stir shallots and garlic in the hot oil until shallots are tender and translucent, about 5 minutes.
-
5
Stir red bell pepper and red pepper flakes into the shallot mixture until bell pepper is slightly softened, 1 to 2 minutes.
-
6
Mix mushrooms into the skillet; season with salt and black pepper. Cook and stir until the mushrooms have given up their liquid and are browned, about 10 minutes more.
-
7
Stir ricotta cheese into the mushroom mixture; remove skillet from heat and set aside.
-
8
Melt butter in another skillet over medium heat. Whisk in flour until smooth, 2 to 3 minutes.
-
9
Whisk milk into flour mixture until smooth; bring to a simmer and whisk constantly until thickened, about 5 minutes. Season with salt and black pepper.
-
10
Coat the bottom of the prepared baking dish with a small amount of the white sauce.
-
11
Arrange 4 lasagna noodles in a single layer over the white sauce.
-
12
Spread about 1/3 of the mushroom mixture over the noodles.
-
13
Pour about 1/3 of the white sauce over the mushroom mixture. Repeat the layers 2 more times, starting with 4 more lasagna noodles.
-
14
Sprinkle Parmesan cheese, mozzarella cheese, and parsley over the lasagna.
-
15
Bake in the preheated oven until cheese is melted and sauce is bubbly, 30 to 40 minutes. Allow lasagna to rest for 10 minutes before slicing and serving.
