Mix the oil, paprika and salt in a bowl, add the sweet potatoes, mix. Spread onto a baking tray lined with baking paper.
Roast for approx. 15 mins. in the centre of an oven preheated to 200°C.
Mix the cream cheese, thyme and lemon zest, season with salt, transfer to a piping bag with a smooth nozzle (approx. 1 cm in diameter), pipe on top of half of the sweet potatoes. Insert two pecan nut halves into each, sprinkle with the thyme leaves.
Mix the avocado, cream cheese, chilli, grapefruit zest and juice, season with salt. Spoon on top of the remaining sweet potatoes.
Heat the oil in a frying pan, fry the prawn tails for approx. 1 min., arrange on top of the sweet potatoes. Top with grapefruit zest.