Preheat your oven to 375°F (190°C) and line a baking sheet with parchment paper for easy cleanup.

In a small bowl, mix 1/4 cup ketchup with the mustard to create a glaze for later.

Combine breadcrumbs and milk in a large mixing bowl, letting them soak for 2-3 minutes until the crumbs absorb the liquid.

Add ground beef, egg, chopped onion, minced garlic, salt, pepper, Worcestershire sauce, and remaining 1/4 cup ketchup to the breadcrumb mixture.

Scoop about 2 tablespoons of the meat mixture and flatten it in your palm. Place a cube of cheese in the center, then fold the meat around it.

Arrange the meatloaf bites on the prepared baking sheet, spacing them about an inch apart. Brush each bite with the ketchup-mustard glaze.

Bake for 20-25 minutes until the internal temperature reaches 165°F (74°C) and the outsides are browned.

Let the meatloaf bites rest for 5 minutes before serving; sprinkle with fresh parsley if desired and serve with extra ketchup for dipping.