In a large bowl, combine the meatloaf mix with Worcestershire sauce, sugar, salt, and pepper, mixing thoroughly until fully incorporated. Divide the mixture into 20 equal portions and form each into a ball.

Flatten each meatball portion with your palm, making a small disc shape. Place a cube of Dubliner cheese in the center and gather the edges to enclose the cheese completely. Roll back into a ball shape, ensuring no cheese is visible.

Heat a large, heavy-bottom skillet over medium heat and add a splash of oil. Once hot, gently add the stuffed meatballs to the skillet and brown on all sides for about 6-8 minutes.

In the same skillet used for browning, add chopped onions and carrots to the drippings, sautéing for 4-5 minutes. Pour in the Guinness lager, scrape up any browned bits, and let it simmer for 2-3 minutes.

Return the browned meatballs to the skillet, cover, and let simmer gently for about 15 minutes, or until cooked through and cheese is melted.

Plate the meatballs and lavishly ladle rich Guinness gravy over them. Serve with Colcannon or pasta.