Preheat oven to 325 degrees. Cut double thickness of heavy-duty aluminum foil to measure 12x16 inches; place on 17x14 inch baking sheet. Trim crusts from bread; cut loaf into 4 lengthwise slices. Place slices side by side on foil. Toast both sides of bread under broiler; butter.
In a heavy saucepan, melt 1 tablespoon butter; blend in flour. Remove from heat; gradually add milk. Cook over medium heat, stirring constantly, until thickened. Cook 2 additional minutes. Stir in 3/4 cup cheese until melted. Beat egg whites and salt until peaks fold over; fold into cheese mixture.
Working rapidly, spread cheese mixture over toasted bread; sprinkle with 1/2 cup cheese. Bread will be cut in 8 equal crosswise sections after baking to make 32 appetizers. Therefore, arrange garnishes of shrimp, anchovies, tomatoes and sliced olives with green pepper and parsley so they will be in center of each individual appetizer.
Bake 15 minutes; place under broiler 1-2 minutes or until lightly browned. Cut; carefully slide foil with appetizers onto serving tray and serve immediately. Yield: 32.
After bread is toasted on both sides as directed above, place slices side by side on foil. Sprinkle 3 cups (12 oz.) shredded Cheddar cheese over all. Garnish as above. Broil 1-2 minutes or until cheese is melted.
