Preheat the oven to 400°F.
Mix the ground meat, egg, breadcrumbs, garlic, onion, salt, and pepper in a mixing bowl until combined.
Shape the mixture into small meatballs and place them on a parchment-lined baking sheet.
Bake the meatballs for about 15 minutes, or until lightly golden and cooked through.
Warm the cranberry sauce, brown sugar, and Worcestershire sauce in a small saucepan over low heat until glossy.
Brush the warm glaze over the hot meatballs.
Slice the slider rolls and place a half slice of cheese on the bottom half of each roll.
Add one glazed meatball to each roll.
Spoon a little extra cranberry glaze over each meatball.
Place the assembled sliders in a baking dish.
Warm them in the oven for about 5 minutes, or until the cheese melts.
Remove from the oven and top with chopped parsley.
Serve the sliders warm.