2 tablespoons olive oil, divided
1 onion, small diced
3 garlic cloves, minced
1 teaspoon red chili flakes
1 tablespoon tomato paste
1 32-ounce can whole, peeled tomatoes
1 teaspoon dried basil
1 pound ground beef
1 cup cottage cheese
1 cup ricotta
2 cups shredded mozzarella cheese
½ cup shredded Parmesan cheese
18-24 jumbo shell noodles, cooked and drained
Salt and pepper to taste
Preheat the oven to 350 degrees Fahrenheit.
Heat 1 tablespoon olive oil in a heavy-bottomed pot. Add the onion and season with salt and pepper. Cook until slightly browned, about 10 minutes. Add the garlic and chili flakes. Cook until translucent, about 1 minute.
Add the tomato paste and fry for 1 minute. Add the tomatoes and basil. Simmer for 20 minutes.
Meanwhile, cook the ground beef in a skillet in the other tablespoon of olive oil. Season with salt and pepper and set aside to cool.
Use an immersion blender or a regular blender to puree the tomato sauce until smooth.
Combine the cooled beef, cottage cheese, ricotta, half the mozzarella and Parmesan.
Spread a thin layer of tomato sauce in the base of a casserole dish. Stuff each of the shells with the beef mixture, and then line up in the dish. Top with a generous layer of tomato sauce and the remaining mozzarella.
Cover with foil and bake for 15 minutes. Remove the foil and continue baking until the top is slightly browned.