Preheat oven to 250 degrees. In a small bowl, add the mayo, diced avocado, and cilantro. Mash together until smooth, then season with salt and pepper to taste.
Slice the slider rolls in half, then add a tablespoon of the dijon mustard to the bottom bun, followed by a slice of provolone cheese. Add the ham, then top with a heaping ½ cup of the leftover pork carnitas. Top with a pickle spear.
Spread a generous layer of the avocado mayo on the top bun, then place on top of the sandwich. Places sandwiches on a baking sheet and bake for 15 minutes, or until the meats are hot and the cheese is melted. Serve immediately.