Heat the grill to high. Grill the bacon on both sides until crisp, then drain on absorbent paper.

While the bacon is grilling, butter the bread and then just before ready to use, mash the bananas well with a fork.

Spread the mashed banana over 4 slices of bread, dividing it equally between them. Cut the grilled bacon

rashers in half and arrange 4 halves on each banana-topped slice of bread. Top with the remaining bread slices and press down well.

Make the batter: sift the flour into a large bowl with the salt. Make a well in the centre. Beat the egg yolks with the water and pour into the well, gradually drawing the flour into the liquid with a wooden spoon. When all the liquid is incorporated, beat well to make a smooth batter.

Beat the egg whites until stiff but not dry, then fold into the batter.

Dip the sandwiches into the batter, ensuring that they are thoroughly and evenly coated on all sides.

Pour enough oil into a large frying-pan to cover the base and heat over moderate to high heat, until sizzling. Add the batter-coated sandwiches and fry until crisp and golden brown on both sides, turning once with a fish slice.

Drain the fried sandwiches on absorbent paper and serve at once.