Brown chicken in a large non-stick skillet until it is cooked through.
Mix together ginger, hot sauce, peanut butter, soy sauce, and lime juice. Stir into chicken.
Lay 4 tortillas on the counter and spread ⅓ cup cheese over each. Spread 1 cup chicken over cheese. Sprinkle some onions, peanuts, and cilantro over cheese. Spread another 3/3 cup cheese over top.
Slide one of the cheese-covered tortillas into a 10-inch skillet over medium heat. (I used an electric griddle.) Place one of the remaining tortillas on top. Press down with a wide spatula to remove any air pockets.
Cover and cook 1 to 2 minutes, checking frequently, until bottom tortilla is crisp and browned.
Turn over, cover and cook 1 to 2 minutes more, or until lightly browned. Repeat this process for remaining quesadillas. Cut into wedges and serve immediately.