Cut the chicken thighs into bite-sized pieces. Add the cornstarch and mix well to coat the chicken.
In a bowl, add the hoisin sauce, peanut butter, soy sauce, sesame oil and minced garlic, and mix well. Don't worry if there are small lumps of peanut butter; they will dissolve in the pan.
Add the oil to a pan and fry the chicken for 5-7 minutes until golden.
Add the sauce to the chicken and mix well. Cook for a few minutes more until the sauce thickens up. Done!
Serve the chicken immediately. You can use green onions, sesame seeds, or crushed peanuts to garnish.