Tuna stuffed baked potatoes

Filling:
4 paking potatoes, baked
1 cup mayonnaise
1/2 cup grated cheddar cheese
1/4 cup chopped green pepper
1/4 cup chopped pimento
1/4 cup chopped scallion
2 7-oz. cans tuna, drained

Topping:
1/4 cup mayonnaise
2 Tbsp. grated cheddar cheese
1 egg white, stiffly beaten

Scoop baked potato from shells. Lightly toss with other filling ingredients. Spoon back into shells. Heat 10 minutes at 400 degrees. For topping: fold mayonnaise and cheese into egg white. Spoon over hot, stuffed potatoes. Heat an additional 10 minutes, until lightly browned.