Using small scissors, make a cut along the top side of the whole prawns. Extract the waste, rinse and set aside.
In a large non-stick skillet or casserole, heat 4-5 tbsp of cooking oil to medium high. Fry the pieces of eggplant until they soften, stirring occasionally. Remove and set aside.
Add another tbsp of oil to the same skillet and fry the onion for 3-4 minutes until translucent.
Return the eggplant to the skillet together with chopped tomatoes and garlic. Add ground cumin and coriander and mix well.
Stir in 1 tbsp of feta crumbles and half of the chopped herbs.
Simmer the sauce for 5-7 minutes for the flavours to blend. Taste the sauce and adjust for salt.
Add the whole prawns and continue to simmer for another 5-7 minutes.
Add the peeled prawns and cook for the final 4-5 minutes until the prawns have turned opaque.
Garnish with the remaining feta crumbles and herbs and serve with loads of fresh or crusty bread.