Mix both cheeses together in a medium Set aside.
Grease a casserole dish liberally and spread a third of the marinara sauce on the bottom of the baking dish.
Top with a third of the uncooked noodles to create a single layer, and a third of the cheese mixture.
Add the sautéed peas and onions.
Continue with the remaining sauce, a layer of lasagna noodles, and cheese mixture in the same pattern until you have a lasagna. Finish with a top layer of shredded mozzarella.
Bake lasagna (covered) at 375°F in the middle rack for 50 minutes and cover with aluminum foil.
For best results, bake uncovered for the remaining 10 minutes so the mozzarella gets nice and golden brown. Serve hot!