Wrap sweet potato in foil and place in oven for 1 hour (or until soft). Next, add the sweet potato to a food processor until you have a smooth puree.
For the dough, mix together the flour, curry powder, salt, and sugar. Add the cold butter and mix until chunky. Add ½-1 cup of the sweet potato puree to the flour and butter mixture. Once combined, add small amounts of water until the mixture forms into a dough. Cool in fridge for 25-30 minutes.
For the meat, heat a pan with 2 Tbsp of olive oil. Add the ground beef and the Caribbean seasoning. When the meat is halfway done, add the red onions. Cook until finished. Place in the fridge for 25 minutes.
Flour a clean surface for your dough. Roll out the dough into a thin layer. Use a bowl to cut circles in the dough.
Beat the egg in a bowl. Place meat mixture in the center of the dough, and brush the edged with the egg wash. Fold the dough over and use a fork to press the edges down.
Place patties on a greased cookie sheet for 20-25 minutes.