In a hot pan with a little oil, sweat onions and brown ground beef (for chili). Season with salt and pepper to taste.
While meat is browning, shape slider patties using ground beef (for sliders) and season with salt and pepper to taste. Remember that your patties will shrink when cooked so size them accordingly. Set aside when done.
Drain meat when done and put in a large sauce pan. Add bbq sauce, fire roasted tomatoes, chili powder, paprika and garlic powder. Stir well and let simmer for 1 hour, stirring occasionally.
Towards the end of the chili cook, grill slider patties to your liking. Add cheese to melt.
Build your slider: bottom bun, bbq sauce, patty & cheese, chili, spicy pickles, crown with top slider bun.