Preheat the oven to 400F. Slice the sweet potato in half lengthways into two pieces. Using a sharp knife cut a criss cross patter through the flash, making sure not to cut the skin.
Place on a lined oven tray and drizzle with the oil. Grind spices in a mortar and pestle then sprinkle half over the sweet potato.
Bake in the preheated oven for 30-40 minutes until fork tender. Remove to a bowl and cool for 10 minutes.
Scoop the flesh into a small bowl then discard skin.
Add the remaining spices and drizzle in the cream, mashing with a fork as you do so.
Mash to desired consistency then serve as a side .