Wash artichoke, cut off 1 inch of top, the stem, and tips of leaves.
Pull off any loose leaves.
Brush cut edges with lemon juice.
Cook in small amount of boiling, salted water till leaves pull out easily, about 30 minutes.
Drain the artichoke, then chill thoroughly.
Meanwhile, combine mayonnaise, caviar (reserve 1 teaspoon caviarfor garnish, if desired), lemon juice, dry mustard, and Worcestershire sauce.
Arrange artichoke and bowl of dressing on serving tray.
Dip caviar mixture with artichoke leaves.