2 tablespoons olive oil
1 medium onion, chopped
3 cloves garlic, minced
Coarse salt and ground pepper
1 1/2 teaspoons dried thyme, or oregano
1 can (28 ounces) whole tomatoes
1 can (28 ounces) crushed tomatoes
2 pounds store-bought ravioli
1 1/2 cups shredded mozzarella cheese
1/2 cup grated Parmesan cheese
Preheat oven to 425 degrees. Heat oil in a large saucepan over medium heat. Add onion and garlic, and season with salt and pepper; cook, stirring occasionally, until softened, about 5 minutes. Add thyme and tomatoes. Bring to a boil, reduce heat, and simmer, breaking up tomatoes with spoon, until sauce is thickened and reduced to about 5 1/2 cups, 20 to 25 minutes.
Meanwhile, cook ravioli in a large pot of boiling salted water just until they float to the top (pasta will continue to cook in oven). Drain pasta; return to pot.
Toss sauce with pasta. Pour pasta into a large gratin dish or 9-by-13-inch baking dish, and sprinkle with cheeses. Bake until golden, 20 to 25 minutes. Cool slightly before serving.