For the scones, place the milk, egg and sugar together in a bowl and whisk until well combined.
In a separate bowl, sieve in the flour and salt and make a well in the centre. Gradually pour in the milk, egg and sugar mixture, whisking until the mixture becomes a thick batter (you may not need all of the milk, egg and sugar mixture).
Stir in the lychees and mix well.
Heat a large frying pan or flat griddle pan until medium hot. Add half of the butter and swirl it around the pan to coat. When the butter is melted and foaming, drop spoonfuls of the scone mixture into the frying pan, making sure there is plenty of space between each spoonful.
Fry the drop scones for 2-3 minutes, or until bubbles begin to form on the surface of the batter. Carefully flip the drop scones over and cook for a further 1-2 minutes, or until golden-brown all over and cooked through. Remove and drain on kitchen paper. Repeat with the remaining scone batter, adding more of the remaining butter to the pan if necessary.
For the sautéed lychees and mango, place a third of the chopped mango into a food processor and blend to a smooth purée.
Melt the butter in a frying pan until foaming, then add the remaining mango and lychees and fry for 1-2 minutes. Add the sugar to the pan and toss to coat, then fry for a further 2-3 minutes, or until the fruit begins to caramelise. Remove the fruit from the pan and set aside, then add the mango purée and stir to mix with the remaining caramelised sugar in the pan.
To serve, pile a few drop scones each onto four serving plates. Top with the sautéed lychees and mango and drizzle over some of the mango sauce. Serve immediately with a scoop of vanilla ice cream alongside.