Mushroom, Sausage, and Roasted Red Pepper Lasagna

3 c. ricotta cheese
1 c. grated Parmigiano-Reggiano cheese
1 egg
1/2 tsp. salt
1/4 tsp. freshly ground black pepper
2 tbsp. extra-virgin olive oil
2 lb. mild turkey Italian sausage, casings removed
1 lb. cremini mushrooms, sliced 1/4-inch thick
1/3 c. chopped fresh flat-leaf parsley
2 jars (each 26 oz.) roasted red pepper pasta sauce
16 lasagna noodles, cooked until just tender
4 c. grated mozzarella cheese

Preheat oven to 350°F. In mixing bowl, stir together ricotta cheese, Parmigiano-Reggiano cheese, egg, salt, and pepper. Cover and refrigerate until ready to use.

In large saute pan over medium heat, warm olive oil. Add sausage and cook, stirring and crumbling with a fork, until lightly browned and cooked through, about 10 minutes. Using a slotted spoon, transfer sausage to a colander set over a bowl and let drain, then transfer sausage to a clean bowl. Add mushrooms to saute pan, increase heat to medium-high and cook, stirring occasionally, until golden brown, about 8 minutes. Transfer mushrooms to bowl with sausage, add parsley, and stir to combine.

Spread 1 c. pasta sauce on bottom of large baking dish. To start the layering process, cover sauce with 1/4 of the lasagna noodles in a single layer. Spread 1/3 of the ricotta mixture over noodles. Spread 1 c. mozzarella cheese over ricotta mixture. Pour 1 c. sauce over mozzarella. Sprinkle 1/3 of the sausage mixture over sauce. Repeat twice, finishing with a layer of sauce. Then top with a final layer of noodles and 1 c. sauce. Sprinkle with remaining mozzarella.

Cover and bake for 40 minutes. Uncover and bake until lasagna is golden and bubbling, about 30 minutes more. Let stand 10 minutes before serving. Serves 12.