Heat a large skillet or braiser over medium heat. Add butter, oil and onions to the skillet and cook until onions are tender. Sprinkle in garlic and cook until fragrant.
Add ground beef and sausage and cook until browned. Stir in seasonings, balsamic vinegar and brown sugar. Pour tomato sauce over ground meat and stir to combine.
Preheat oven to 375 degrees.
Sprinkle cheese tortellini into the meat sauce and cover and cook over medium-low heat for 4-5 minutes. When done, stir in cottage cheese.
If not using an oven safe braiser, transfer pasta to an oven safe dish and sprinkle top with mozzarella and parmesan cheese. Bake uncovered for 20 minutes. When done, remove from oven and allow to cool before serving.