In a large mixing bowl, combine your choice of ground meat, breadcrumbs, finely chopped onion, minced garlic, and spices. Use your hands to mix everything until well-combined—about 2-3 minutes. Add one egg to bind the ingredients together, ensuring a cohesive mixture. Once mixed, cover and let it rest for 15 minutes.

Preheat your oven to 400°F (200°C). With clean hands, scoop out portions of the meat mixture and roll them into uniform balls, around 1 inch in diameter. Place the meatballs on a baking sheet lined with parchment paper, ensuring they’re spaced evenly apart.

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

While the meatballs are baking, prepare the sauce by combining ketchup, Worcestershire sauce, brown sugar, mustard, and red pepper flakes in a saucepan. Heat over medium heat, stirring occasionally until well blended and bubbly, about 5-7 minutes.

Once the meatballs are done baking, transfer them to the saucepan with the warm sauce. Stir gently to coat each meatball thoroughly. Simmer for an additional 5 minutes on low heat.

Transfer your cocktail meatballs to a serving platter or keep them warm in a slow cooker on low. Garnish with fresh herbs if desired.