Sprinkle each quail inside and out with salt and pepper.
Heat the butter in a skillet, preferably of black iron, and when it is quite hot add the quail. Brown the birds on all sides, turning occasionally to brown evenly, about 5 minutes.
Transfer the quail to a platter. Sprinkle the fat remaining in the skillet with flour. Cook, stirring rapidly, until the flour starts to take on color. Add the stock, stirring rapidly with a wire whisk. Add the Worcestershire sauce. Return the quail to the skillet and turn them in the sauce. Cover with a tight-fitting lid. Place in the oven and bake45 minutes or longer, until the quail are thoroughly tender.
Serve each quail on a toast triangle with sauce spooned over.