Add the mustard, honey, beer, cornstarch, ¼ teaspoon salt, ½ teaspoon pepper, garlic and lemon juice to a bowl. Whisk together until smooth.
Melt the butter in an oven safe skillet over medium high heat. Sprinkle chicken with salt and pepper on all sides. Sear chicken on both sides until browned.
Pour mustard sauce over the chicken and bake until the chicken is cooked through, about 22 to 25 minutes.
Plate chicken over rice, if desired. Spoon desired amount of sauce over chicken.
Notes
Choosing the right beer: Look for a medium hopped, citrusy American pale ale to find the right balance with the strong mustard notes in this recipe.