1. Form the ground beef into 12 balls. Season with salt and pepper.
2. In a pan, fry the meatballs in a little oil for 4-5 minutes until lightly browned. Remove from the pan.
3. Sauté the finely chopped garlic and onions in the oil until clear. Add the tomatoes and cook through for 5 minutes. Season to taste with thyme, salt, pepper and balsamic vinegar.
4. Blend the sauce using a handheld blender, return the meatballs to the sauce and heat through for about 5 minutes over medium heat.
6. Cut the Castello Mature Cheddar into small slices and place two quarter slices on each meatball. Pop the pan in a pre-heated oven for 2 minutes until the cheese has melted.
7. Spread the slider buns with mayonnaise on both the top and bottom. Place a lettuce leaf on each bottom bun, then add the meatballs with cheese.
8. Pour a little extra sauce from the pan over each slider.
You can always make these as full-size burgers if you want. Sliders are mini-burgers. One of the advantages is that you can prepare most of the ingredients beforehand, so if your friends drop by and you want to serve burger snacks, it doesn’t take much preparation.