1. Melt butter in oil in a large, heavy skillet, swirling the mixture over low heat.
2. When the butter starts to foam, add the chicken; cook for 15 minutes, turning once, until no linger pink in the center. Transfer to a plate and cover to keep warm.
3. Add the garlic to the drippings in the skillet and fry for 30 seconds. Add 2 tablespoons water, the lemon zest and juice, and the parsley. Stir in salt and freshly ground black pepper to taste.
4. Simmer the parsley, garlic and lemon butter for 1 minute, then spoon over the chicken. Serve immediately