Healthy & Delicious: Lighter Spinach Lasagna

1 tablespoon olive oil

1 cup chopped onion

1 cup sliced mushrooms

4 cloves garlic, minced

1 7-ounce jar roasted red peppers, drained and chopped

1 10-ounce package frozen spinach, thawed and very well drained

1 15-ounce container part-skim ricotta

1 cup part-skim shredded mozzarella cheese

1/2 cup grated Parmesan cheese

3 egg whites, lightly beaten

1 teaspoon dried basil, crushed

1 teaspoon dried oregano, crushed

1/4 teaspoon freshly ground black pepper

1 24-ounce jar your favorite meatless pasta sauce

1/4 cup grated Parmesan cheese