In a large bowl, mix the ground turkey with the other patty ingredients (except for the egg and the cheese) and knead. This is probably the most fun part of the process! Once you have a uniform mix, add the egg and keep on kneading. Still more fun!
Take 1/4 of the mixture and extend it on the palm of your hand. Place 1/4 of the cheese in the center and fold everything up to a ball, keeping the cheese sealed inside. Carefully form the ball into a patty roughly the shape of your ciabattas. Repeat for the other three patties.
Heat up a griddle over medium-high heat and grill the patties (approx. 5 minutes per side). If you have any leftover cheese, you can place it on top of the patties after flipping.
Assemble the sliders: spread mayo and mustard on both halves of the ciabatta, layer lettuce, tomato, onion, avocado, pickles, and patty. Top it off with a dash of ketchup. (actually, this is just how we made them, you can assemble your sliders to your heart's desire) Enjoy!
