4 to 6 servings
On a sheet of wax paper, dredge chicken pieces in flour, coating each lightly. In a large heavy skillet, melt butter or heat oil over moderate heat; add chicken pieces and brown thoroughly, about 10 minutes per side. Season chicken pieces with salt and pepper to taste. Remove chicken to a warm plate, draining drippings back into skillet; cover chicken with aluminum foil to keep warm. Add garlic and onion to hot skillet and sauté, stirring frequently, until crisp tender but not browned. Reduce temperature to low; add thyme sprigs, mushrooms, sweet red pepper, white wine or sherry, and parsley; simmer, uncovered, for 10 minutes. Return chicken pieces to skillet, coating each piece liberally with sauce. Continue to simmer for 3 to 4 minutes until chicken is heated through. Adjust seasoning to taste. Remove thyme sprigs stems from sauce before serving; leaves should have been absorbed into the sauce during cooking action.
To serve, arrange a chicken piece or pieces on each plate. Spoon a small amount of sauce over each serving. Garnish each with a sprig of parsley and thyme. Pass any remaining sauce in a sauceboat.
Note: For a thicker sauce, blend 1½ teaspoons flour into the sauce with the mushrooms. Cook as previously directed.