Cut loaf in half horizontally; hollow out top and bottom, leaving 1/2 inch (1 cm) shell. Save removed bread for another use. Beat eggs with water; season with salt and pepper. Spray an 8 inch ( 20 cm) non stick skillet with cooking spray. Pour in half of egg mixture and cook over medium heat. As mixture sets at the edges, with spatula, gently lift cooked portion to allow uncooked egg to flow underneath. Cook until bottom is set and top is almost set. Slide onto plate; let cool completely. Repeat procedure with remaining egg mixture. Brush inside bottom and top of bread with caesar dressing. Layer bottom of loaf with one omelette and half of sliced roast beef, gruyere cheese, tomato, salami, artichokes, salad greens and chicken. Repeat layers with remaining ingredients. Replace bread top; wrap tightly in plastic wrap. Refrigerate at least one hour before slicing into wedges.