Prepare the coleslaw: Whisk the buttermilk, mayonnaise, apple cider vinegar, sugar and remaining half of the green onions from the meatballs in a large bowl and add the cabbage, stirring to coat evenly. Season to taste with salt and pepper.
(This is where, if you’re bothered enough to make your own barbecue sauce, you can do so using the quick recipe at the end. But there’s really no need to do this to make a great dumpling slider of meat, I promise.)
Toast your buns: In a large skillet, the same one where you will cook your meatballs, melt a tablespoon of butter over medium heat. Place your buns, cut side down, in the pan. Cook until cut sides are golden brown, about 1 to 2 minutes. Transfer to a plate or dish where you will assemble your sliders.
Cook the crushed meatballs: Remove the chicken meatball mixture from the fridge and, using wet hands to achieve a smoother shape, roll it out to the size and number of meatballs you want – this is determined by the size of your buns. Be sure to roll the meatballs smaller than the bread so they fill it up when crushed.
Heat your large skillet over high heat for a minute, then coat it with about 2 tablespoons of oil. Place your first meatballs in the skillet and let them sear for 30 seconds to 1 minute before using a heavy spatula to flatten them until they are about 1/2 inch thick. Season the meatballs with an extra pinch of salt and pepper. Cook until crispy and deeply browned on the bottom, about 3 to 4 minutes – reduce the heat to medium-high if they cook much faster – and flip each, cooking on the second side until until it is also golden on the bottom, another 2 minutes. 3 minutes away. Transfer meatballs to prepared buns and repeat with remaining meat.
To finish: Drizzle barbecue sauce over each meatball, top with a few slices of pickle and a small pile of coleslaw, and eat immediately.
Quick BBQ Sauce: Mix 1/3 cup of ketchup, 3 tablespoons of molasses and apple cider vinegar, 1 tablespoon of Worcestershire sauce and 1 teaspoon of chili powder or smoked paprika (or half of each) in skillet and bring to a boil, stirring, over medium-high heat. heat. Reduce the heat to medium and continue cooking, stirring, for 2 to 3 minutes. Season to taste with salt and freshly ground black pepper. Pour into bowl to serve; wipe out the pan and continue to use it for toasting buns and cooking meatballs.