Step 1

In a large skillet add the butter until melted.

Step 2

Add the onions, cooking until tender (about 3 minutes).

Step 3

Add the garlic, celery, and carrots and cook for another 3-5 minutes.

Step 4

Add the meatballs and brown on each side (even though they are already cooked, it gives them extra flavor).

Step 5

Pour everything into a crock pot/slow cooker except the cornstarch and cheese.

Step 6

Cook on high for 3-4 hours.

Step 7

In a mixing bowl, combine the cheeses and cornstarch, tossing to coat.

Step 8

Stir the cheese and cornstarch into the pot to thicken it and serve. Enjoy!