Sweet and Sour Meatballs

Name: Sweet and Sour Meatballs
Ingredients: 1/2 cup loosely packed brown sugar; 1/2 cup rice wine vinegar; 1/4 cup ketchup; 1 tablespoon low-sodium soy sauce; 2 1/4 cups pineapple juice; 1 tablespoon cornstarch; One 25-count bag All-Purpose Meatballs (still frozen is fine), recipe follows; 1 tablespoon sriracha hot sauce; 1 cup drained small pineapple chunks; Steamed long-grain rice, for serving; 2 tablespoons sliced green onions, for garnish; 5 pounds ground beef; 1 1/2 cups plain breadcrumbs; 1/2 cup milk; 1/4 cup heavy cream; 1/4 cup chopped fresh flat-leaf parsley; 2 tablespoons grainy mustard; 1 teaspoon salt; 1 teaspoon freshly ground black pepper; 1/2 teaspoon red pepper flakes; 4 large eggs; 2 tablespoons olive oil