Place the eggs in a saucepan and cover with water. Bring to the boil and simmer for 8 minutes. Drain and run under cold water, until the eggs are cool. Peel under running water.
In a bowl, mix together the mayonnaise and mustard. Season with black pepper. Chop the eggs and fold into the mayonnaise mixture with the mustard and cress.
Open out the sandwich thins and arrange the lettuce over four halves. Spoon the egg mixture over the lettuce and top with the other sandwich thin. Serve with grapes, apples and cucumber.
TIP: Make up the egg mayonnaise mixture ahead and keep sealed in an airtight container in the fridge until you are ready to use it.