In a small bowl, combine all of the ingredients for the jalapeño relish. Cover and refrigerate until ready to use.
In a small bowl, combine the crumbled bacon and grated cheese. Use your hands to form the bacon and cheese mixture into 14 small balls. They’ll be very coarse balls, but the heat from your hands will help them stick together.
Place the ground beef salt and black pepper in a medium bowl. Mix until just combined. (Just use your hands, people.)
Now it’s time to make your slider patties. Divide the beef into 14 balls (each should be about a heaping tablespoon.) Flatten each ball into a pancake about a ¼-inch thick. Place one of the bacon-cheese balls in the center of the beef. Gently fold the beef around the cheese, making sure it’s completely sealed within the beef, and flatten the patty slightly. (Each patty should be 1¾-inches in diameter.)
Heat a tablespoon of oil in large skillet or pan over medium-high heat. Add the sliders and cook for about 1½-2 minutes on each side until the beef is cooked through and the hidden cheese has had time to melt. Depending on the size of your pan, you may find it easier to do this in two batches.
If you like toasted buns (who doesn’t?), now is the time to throw them on the grill/under the broiler for 30 seconds.
Place each slider on a bun and add a dollop of ketchup, if you’re into that. Top with jalapeño relish and serve immediately.