Place the chocolate chips in a heat-proof bowl, and set aside.
Bring the milk and butter to a gentle boil in a pan. When the butter is melted, pour the milk over the chocolate chips. Stir until the chocolate is completely melted and smooth.
Place the bowl of melted chocolate over a pan of simmering water to keep warm.
Wash and hull the strawberries. Cut in half if they are large.
Juice the lemon. Reserve in a bowl.
Peel and slice the bananas into large chunks. Dice the apple into dice. Toss both the apples and the bananas in the lemon juice to prevent any browning.
Using a serrated knife, remove the pineapple's peel, and cut into bite-sized chunks.
Place the fruits in bowls, and allow everyone to dip the fruits into the warm chocolate using skewers or forks.
«Use whatever fruits that are ripe and in season. The chocolate sauce can be kept warm for up to an hour, but for longer periods, you may want to add about 100ml of vegetable oil to keep the sauce fluid.»