In a large frypan over medium heat cook the mince, onion and garlic until brown. Add the tomato sauce, tomato paste, salt and oregano and stir until well incorporated. Cook until heated through.
In a large bowl mix together the cottage cheese, grated Parmesan cheese and grated mozzarella cheese.
Spoon a layer of the meat mixture onto the bottom of the slow cooker. Add a double layer of the uncooked lasagna sheets. Break to fit sheets into slow cooker. Top sheets with a portion of the cheese mixture. Repeat the layering of sauce, sheets, and cheese until all the ingredients are used.