Pork Tenderloin in Pan Sauce without yeast fettuccine mayonnaise

1 lb pork tenderloin, trimmed of fat and silver skin and cut cross wise into 6 pieces 1/2 cup flour salt and pepper 1 egg , beaten (for egg bath) 2[...]

1 tablespoon butter 1 small onion , finely chopped 1 tablespoon flour 1 cup chicken stock 2 tablespoons Dijon mustard 2 tablespoons pure maple syrup 1[...]