First peel the sweet potatoes, cut them into small pieces and boil in a pan of salt water for around 20 minutes until soft.
While the potatoes are cooking, season the fillet with salt, then place on the grill with the asparagus and the tomatoes. Grill the meat on each side for about 3-4 minutes (depending on how well done you want it). Garnish the meat with rosemary sprigs for flavour.
Then place the prawns on the grill and grill for around 3 minutes on both sides until they change colour.
When the potatoes are done, remove the excess water and mash the hot potatoes. Then stir in butter and milk and season with salt, pepper and curry powder.
As soon as the meat is cooked, you can plate and serve! Have fun barbecuing and enjoy your meal!