Combine ground beef, bread crumbs, minced onions, milk, egg, parsley, salt, pepper, and Worcestershire sauce in a large bowl.

Gently mix until just combined to avoid overworking the meat.

Shape the mixture into 1-inch meatballs.

Preheat oven to 375°F (190°C).

Place meatballs on a broiler pan, ensuring they are not touching.

Bake in the preheated oven for 20 minutes, or until cooked through.

While the meatballs are baking, prepare the sauce.

In a saucepan, combine chili sauce and grape jelly.

Heat over medium heat, stirring constantly until the jelly is completely melted and the sauce is smooth.

Once the meatballs are baked, add them to the saucepan with the chili-grape jelly sauce.

Stir gently to coat the meatballs thoroughly with the sauce.

Reduce heat to low and simmer, uncovered, for 30 minutes, stirring occasionally.

Serve hot as appetizers.