Soak the no-boil lasagna noodles in warm water for 10 minutes. (Or, cook regular noodles according to package directions, except omit salt.)
Meanwhile, in a large skillet cook and stir zucchini or yellow summer squash, mushrooms, and onion in hot oil over medium heat for 6 minutes or until zucchini is tender. Drain well.
In a small bowl stir together ricotta cheese, Parmesan cheese, and black pepper. To assemble, place 3 lasagna noodles in a 2-quart square baking dish, trimming to fit as necessary. Top with ricotta mixture, half of the vegetable mixture, half of the Red Pepper Sauce, and half of the mozzarella cheese. Layer with remaining lasagna noodles, vegetables, and sauce.
Bake lasagna, uncovered, in a 375 degree F oven for 30 minutes. Sprinkle with remaining mozzarella cheese and the tomato; bake 5 minutes more or until heated through. Let stand 10 minutes before serving. Makes 6 servings.
Red Pepper Sauce
In a large skillet cook 3 cups chopped red sweet peppers and 4 whole cloves garlic in 1 tablespoon olive oil over medium heat about 20 minutes, stirring occasionally. (Or, you may use one 12-ounce jar roasted red sweet peppers, drained. Omit cooking step.) Place pepper mixture in a blender container. Cover; blend until nearly smooth. Add 1/2 cup water, 1/4 cup tomato paste, 2 tablespoons red wine vinegar, and 1 tablespoon snipped fresh oregano or 1/2 teaspoon dried oregano, crushed. Cover; blend with several on-off turns until oregano is just chopped and mixture is nearly smooth. Return to skillet. Cook and stir over medium heat until heated through. Makes about 2 cups.