Step 1

Preheat the oven to 325º F. Line a baking sheet with parchment paper or foil, arrange a wire rack onto the lined baking sheet, spray the wire rack well with nonstick cooking spray and set aside.

Step 2

Mix together ground beef, onion, egg, milk, salt, pepper, bread crumb, and Worcestershire sauce in a medium mixing bowl until well combined. Scoop the mixture into about tablespoon sized balls and roll firmly between palms of hand to form meatballs. Place onto the wire rack lined baking sheet.

Step 3

Once all of the meatballs are formed, bake until the meatballs are cooked through, about 20 minutes.

Step 4

Meanwhile, combine all of the ingredients for the sauce in a large skillet set over medium heat. Cook, stirring occasionally, until the sauce has thickened, about 10 minutes.

Step 5

Arrange the cooked meatballs in a slow cooker and pour the thickened sauce over the meatballs. Gently stir the meatballs to coat with the sauce. Secure the lid on the slow cooker and set on low setting to keep warm as serving.