Instructions:
Cook Ground Beef: In a large skillet over medium heat, cook the ground beef until browned. Add the chopped onion and minced garlic, cooking until the onion is softened. Drain any excess fat.
Prepare Meat Sauce: Stir in the marinara sauce, diced tomatoes, oregano, basil, salt, and pepper. Bring to a simmer and cook for 5 minutes.
Assemble Lasagna: Lightly grease the slow cooker. Spread a thin layer of the meat sauce on the bottom. Layer frozen cheese ravioli over the meat sauce, followed by another layer of meat sauce. If using, add ricotta cheese and sprinkle with mozzarella and Parmesan. Repeat the layers until all ingredients are used.
Cook Lasagna: Cover and cook on low for 4-5 hours or on high for 2-3 hours, until the ravioli is tender and the cheese is melted and bubbly.
Serve: Let the lasagna sit for 10 minutes before serving. Garnish with fresh basil or parsley and enjoy hot with a side salad or garlic bread.
