Directions

1. Preheat oven to 350°F. Lightly coat a 12-inch pizza pan or baking sheet with nonstick cooking spray. Place dough on pan, seam side down. Pinch ends of loaves together to form one 10-inch ring. Cut shallow diagonal slices in top of dough. Brush with egg white; top with seeds.
2. Bake 25 minutes or until crust is golden brown. Remove to a wire rack; let cool completely (about 1 hour).
3. With a serrated knife slice loaf in half horizontally. Layer lettuce leaves, tuna salad, onion and tomatoes on bottom half of loaf. Cut cheese slices in half diagonally; place on tomatoes. Cover with top half of loaf, cut into wedges, and serve.