1. Mix the flours together well.
2. Break the eggs into a bowl and beat them lightly. Add the eggs to the flour and mix well again.
3. Add the milk, a little at a time, making sure there are no lumps. When the batter is smooth, and you have added all the milk, melt the butter and add it to the mixture.
4. Leave to rest for 30 min.
5. Add the water and the rum.
6. Heat a shallow frying pan or hot plate over a medium heat.
7. Grease the pan well. The easiest way is to use a potato. Cut one in half and stick a fork into the skin side of one of the halves. Then dip the cut flat side into a little oil and use that to grease the pan or hot plate.