When the olive oil and butter start to sizzle, add the chicken. Do not overcrowd the pan or the chicken will steam. The chicken may need to be cooked in two batches. Cook for 3-4 minutes until golden brown. With a meat fork or tongs, carefully flip the chicken away from you. Cook for an additional 3-4 minutes or until the chicken reaches an internal temperature of 165 degrees Fahrenheit. Transfer the chicken to a wire rack set over a sheet pan. Alternately place chicken directly on the sheet pan. Place in the oven to keep warm. Or tent with foil to keep warm.