Combine tuna fish, steamed bhetki, mayonnaise mixed with egg yolks, boiled peas and carrots, chopped capsicum, finely chopped onions, breadcrumbs, lemon juice, mustard and salt and pepper to taste.
Put mixture into a baking dish.
Pipe the fluffy mashed potatoes with 1 egg yolk, 2 tbsps. cream and 2 tbsps. butter around the sides of the dish, making a decorative border, leaving the centre empty. Bake at 180 degrees C for 15 mins.
For the Mayonnaise Meringue:
Beat egg whites till stiff. Fold in 1/4 cup mayonnaise.
Pile egg whites mixture within the border to cover the baked tuna.
Grill or bake in a very hot oven for 2 mins until mayonnaise meringue is golden brown.