Wash and dry the lettuce and place it on a large platter.
Cook the egg for 5 minutes in boiling water, let cool, quarter lengthwise.
Remove the ends of the green beans. In a steamer pot, steam the green beans for 5-7 minutes. Remove the green beans with tongs. Add more water to the steamer. Steam the potatoes for 10 minutes. The potatoes should be cooked through but not soft. Slice the potatoes into 1/2 inch slices. Cut the tomatoes in half. Prepare the roasted peppers and onions and the garlic and mustard dressing recipes. Rinse and drain the white beans.
Grill the tuna on high heat for 3-4 minutes on each side for rare tuna. When cool slice into 1 inch slices.
Arrange the tuna, egg, whole green beans, potatoes, beans, tomatoes and roasted peppers and onions on the lettuce leaves. Dress with 2 tablespoons of the garlic and mustard dressing.
Nutritional information per serving: 290 calories, 8 g fat, 1.5 g saturated fat, 80 mg cholesterol, 110 mg sodium, 31 g carbohydrates, 7 g fiber, 25 g protein.