Heat 1 tablespoon of olive oil in a skillet over medium heat. Add the finely chopped red onion and sauté for 2-3 minutes until softened.

Add the shredded chicken to the skillet and pour in the barbecue sauce. Stir until the chicken is evenly coated and heated through, about 5 minutes. Remove from heat.

Preheat your oven to 350°F (175°C). Place the halved slider buns on a baking tray.

Spread a thin layer of mayonnaise on the bottom halves of the slider buns, followed by a small dollop of mustard.

Spoon the BBQ chicken mixture evenly onto the bottom halves of the slider buns.

Sprinkle shredded mozzarella cheese on top of the BBQ chicken. Place the baking tray in the oven and bake for about 5 minutes, or until the cheese is melted.

While the sliders are in the oven, season the coleslaw mix with a pinch of salt and pepper. Toss well to combine.

Remove the sliders from the oven and top each one with a small handful of the coleslaw mix. Add pickles if desired.

Place the top halves of the buns over the toppings and serve immediately.