Spread 4 tsp mayonnaise on both sides of 2 slices of white sandwich bread. With a medium heart-shaped cookie cutter, cut centres from bread. In a 30cm nonstick frying pan, melt 1 tbsp butter on medium. Add bread (and centres) to frying pan. Cook for 5 minutes or until golden brown. Turn bread over. To each heart-shaped hole, add 1 large egg; sprinkle eggs with a pinch of salt and pepper. Reduce heat to medium-low. Cook for 5 to 7 minutes or until whites are set. Sprinkle with finely chopped capers and herbs (such as parsley, chives or basil) if desired.