Preheat the oven to 425°F.

In a large nonstick skillet, heat 1 teaspoon olive oil over medium-high heat. Add 3 cups thinly sliced mushrooms, 1 cup chopped sweet onion, and 1 cup chopped red bell pepper; sauté about 4 minutes, stirring occasionally, until the vegetables are tender.

Add 3 cups chopped fresh spinach, 1 tablespoon chopped fresh oregano, and 1/4 teaspoon freshly ground black pepper to the skillet; sauté about 3 minutes, stirring, just until the spinach wilts. Remove from heat.

Place the One 16-ounce carton nonfat cottage cheese in a food processor and process until very smooth.

In a large bowl, combine the cooked vegetable mixture, the processed cottage cheese, 4 cups hot cooked penne (about 8 ounces uncooked), 2 cups shredded roasted skinless, boneless chicken breast, 3/4 cup shredded reduced-fat sharp cheddar cheese, 1/4 cup grated fresh Parmesan cheese, 1/2 cup 2% reduced-fat milk, and the One 10.75-ounce can condensed reduced-fat, reduced-sodium cream of mushroom soup. Stir until evenly mixed.

Spoon the mixture into a 2‑quart baking dish and spread evenly. Sprinkle with the remaining 1/4 cup shredded reduced-fat sharp cheddar cheese and the remaining 1/4 cup grated fresh Parmesan cheese.

Bake at 425°F for 25 minutes, or until the top is lightly browned and the casserole is bubbly. Let stand 5 minutes before serving.