Put 4 or 5 ice cubes in a large old-fashioned glass and fill 3/4 full with Clamato juice. (Clamato may be mixed 1/2 and 1/2 with any other favorite tomato or veggie juice). Add the vodka, Worcestershire, Tabasco, and Horseradish and stir thoroughly with a spoon or swizzle. Twist the lime slice over the glass edge and stick a scallion in as a casual stirrer and delicious finish to the drink.
Serve in a Old Fashioned Glass