Olive-Stuffed Chicken with Almonds

Pat chicken breasts dry, then cut a 2-inch-long horizontal slit in thickest part of each. Stuff each chicken breast with 1 1/2 teaspoons olives, then season with salt and pepper. Heat 1 tablespoon butter in a 12-inch nonstick skillet over moderate heat until foam subsides, then toast almonds, stirring often, until a few shades darker, 5 to 8 minutes. Transfer with a slotted spoon to a cutting board to cool (do not clean skillet). Increase heat to moderately high, then add chicken breasts, skin sides down, to butter remaining in skillet and sprinkle with remaining olives. Sauté chicken breasts until skins are golden brown, 8 to 10 minutes. Turn chicken breasts over and cook, covered, over moderate heat until just cooked through, 5 to 7 minutes more, then transfer with tongs to plates. While chicken is cooking, chop almonds. Add remaining tablespoon butter and 3 tablespoons water to skillet and heat, stirring, until butter is melted. Stir in almonds, parsley, and pepper to taste. Spoon sauce over chicken.