Directions

1. 1

   In a large mixing bowl, combine the beaten egg, bread crumbs, milk, grated Parmigiano Reggiano, minced onion, and minced garlic.

2. 2

   Stir the mixture until all ingredients are evenly incorporated.

3. 3

   Add the sausage meat to the bread crumb mixture and gently fold together until combined, being careful not to overmix. Using a cookie scooper or your hands, form approximately 24 meatballs of uniform size, rolling each gently between your palms.

4. 4

   Insert a slow cooker liner into your slow cooker, pressing it snugly against the bottom and sides and folding the rim over the top edge of the slow cooker bowl.

5. 5

   Carefully place the formed meatballs into the lined slow cooker. Cover with the lid and set to low heat (approximately 275°F if your slow cooker has a low setting).

6. 6

   Cook for about 1 hour, or until the pork sausage is cooked through with no pink remaining in the center (internal temperature of 160°F when measured with a meat thermometer).

7. 7

   Pour the spaghetti sauce over the cooked meatballs and stir gently to coat. Replace the lid and continue cooking on low for 10 to 15 minutes, until the sauce is heated through.

8. 8

   Carefully remove the lid and allow steam to escape for a moment. To serve, place one meatball and a light drizzle of sauce inside each slider roll. Allow the slow cooker to cool completely, then remove and discard the liner.