Preheat oven to 350 degrees Fahrenheit (175 degrees Celsius). Lightly grease a 13x9-inch baking dish.

In a medium saucepan, combine chili sauce, grape jelly, and Dijon mustard.

Cook over low heat, stirring constantly, until the jelly is melted and the mixture is smooth.

Place the thawed meatballs in the prepared baking dish.

Spoon the chili sauce mixture evenly over the meatballs, ensuring they are well coated.

Cover the baking dish tightly with aluminum foil or a lid.

Bake for 1 hour, stirring occasionally to prevent sticking and ensure even cooking.

Serve the meatballs warm, with toothpicks for appetizers or over rice or pasta as a main course.