Heat oil and 1 tablespoon of butter in a large non-stick skillet over high heat.

When the butter is melted, add the chicken. Sprinkle with salt and pepper, then cook until it changes from pink to white and starts to brown.

Add the remaining 2 tablespoons of butter, honey, garlic, and vinegar. Bring to a simmer. Turn the chicken to coat in the sauce until it is golden and caramelized.

Once the chicken is browned all over, remove it from the heat. Pile chicken onto mashed potatoes, and drizzle with the sauce in the pan. Garnish with parsley if desired.