1. For the marinade, mix 1 tablespoon of oil, worcestershire sauce, 2 crushed cloves of garlic, half of lime juice, paprika and cumin in a bowl.
  2. Spoon in the prawns and marinate them in the fridge for 1 hour.
  3. Cook the cubes of sweet potato in water until al dente, rinse them in a colander with cold water.
  4. Pour the orange juice into a pan and add the shallots, 1 clove of garlic and the cardamom.
  5. Reduce the juice halfway over medium heat and allow to cool.
  6. Heat the remaining 3 tablespoons of oil in a wok and stir fry the sweet potato on high heat until light brown.
  7. Scoop the ingredients into a large bowl.
  8. Stir fry the prawns in the same pan.
  9. Add bell pepper, spring onions and carrots and cook until al dente.
  10. Finally add the orange mixture.
  11. Put the contents of the wok in the bowl with the sweet potato, add avocado, mango, cherry tomatoes and salt and pepper to taste.
  12. Spoon lightly and garnish the salad with coriander and grapefruit slices.

Do not throw away the squeezed lime, but put the halves in a jug of cold water. That looks nice on the table and is nice to drink.