Toss the chicken breast with the corn starch, and add a pinch of kosher salt and pepper.
Add cooking spray or olive oil spray to the frying pan and preheat over medium-high heat.
Sear the chicken on all sides (working in two batches) until golden on the outside (it will not be cooked through). Set aside on a plate.
Combine the soy sauce, Hoisin sauce, brown sugar, unsweetened applesauce, sesame oil, rice wine vinegar, ginger, chicken broth, minced garlic, and sriracha in a bowl.
Add the chicken to the bottom of a slow cooker, and pour the sauce on top. Stir to combine thoroughly.