Warm the buns in a toaster oven or warm in the microwave for 30 seconds. Spread 1 tablespoon of ranch sauce on each of the ciabatta slices.
Heat half of the chicken in a fry pan covered with a lid or place on a plate and warm in the microwave for 30 seconds. Top with 2 slices of cheese and heat until cheese melts. transfer to the bottom bun and then top with slices of avocado and the top bun. Serve warm.
*You can sub creamy havarti, spicy horseradish cheese, or hot habanero if you can find it.