1In 4-quart saucepan, melt butter over medium heat. Cook onion and garlic in butter 10 to 12 minutes, stirring frequently, until golden brown.
2Sprinkle flour and pepper over onion mixture. Cook 1 minute, stirring constantly. Slowly add half-and-half, stirring constantly. Stir in meatballs.
3Cook 15 to 20 minutes, stirring occasionally, until sauce is thickened and meatballs are hot. To serve, place in 1 1/2- to 2-quart slow cooker on Low heat setting. Meatballs will hold up to 2 hours in slow cooker. Garnish with chopped fresh parsley.