600g canned diced tomatoes
400g canned crushed tomatoes or passata
1 tsp onion powder
1 tsp dried Italian seasoning
1 tsp kosher salt
1 tsp balsamic vinegar
Cooking spray
650g frozen cheese ravioli (do not thaw)
450g grated mozzarella cheese (about 2 cups)
Place the diced tomatoes and their juices, crushed tomatoes, onion powder, Italian seasoning, salt, and vinegar together in a large bowl and stir to combine.
Coat slow cooker with cooking spray. Pour 1/4 of the tomato sauce into the bottom of the slow cooker. Scatter 1/3 of the ravioli evenly over the sauce. Sprinkle 1/4 of the cheese over the ravioli. Repeat the layers of sauce, ravioli, and cheese two more times. Pour the remaining tomato sauce over the top, then sprinkle with the remaining cheese.
Cover and cook on the LOW setting until the sauce bubbles, the ravioli is heated through, and the cheese melts and browns, about 8 hours.
Notes:
– Traditional cheese ravioli makes for a classic lasagna, but with an abundance of ravioli varieties available in the market, you can make each meal different.
– Meat variation: Sautee 500g of ground beef, turkey, or sausage with 1 small diced onion on the stovetop over medium heat. Drain the fat and layer into the lasagna between the ravioli and cheese.