Melt butter with olive oil in a large saucepan or skillet.
Add onions and garlic and sautee for about 3 minutes, stirring often.
Add meatballs and brown on all sides.
Add tortellini, crushed tomatoes, water, oregano and Italian seasoning. Bring to a boil, reduce heat to medium low and simmer for about 12 to 15 minutes OR until tortellini is cooked.
Stir in ½ cup of mozzarella cheese.
Sprinkle remaining cheese on top. Cover skillet and let simmer for 2 to 3 minutes or until the cheese is melted.
Remove from heat and let stand for 10 minutes before serving.
Notes
Please note, that the nutrition value can vary depending on what product you use. The information below is an estimate. Always use calorie counter you are familiar with.
You need to thaw the meatballs before using them in the recipe.
You can use spaghetti sauce in place of crushed tomatoes.