Cut the bread in half lengthwise. Hollow out the bread leaving a 1 inch shell.
Combine the tuna, mayonnaise, lemon juice, tarragon, and pepper.
Place the lettuce leaves on the bottom of the bread. Top with tuna salad. Layer the tuna with egg whites, tomato slices and pickles. Wrap tightly in plastic wrap and refrigerate until ready to serve.
To serve slice diagonally and place on serving platter.
This recipe yields 4 servings.
Exchanges Per Serving: 2 Very Lean Protein, 3 1/2 Carbohydrate (3 Bread/Starch, 2 Vegetable).
Nutrition Facts: 356 calories (11% calories from fat), 22 g protein, 4 g total fat (1.0 g saturated fat), 56 mg carbohydrate, 4 g dietary fiber, 18 mg cholesterol, 990 mg sodium*.
* Not appropriate for a low-sodium diet.