1. Start by making the marinade for the prawns. In a large bowl mix the olive oil, paprika and juice of 2 limes and set aside.
2. Make the guacamole by chopping the red onion and chilli into a bowl. In a mixer or blender, blitz the avocado and garlic, pouring in the olive oil and lime juice. Blitz until you get a smooth puree.
3. Add the blitzed mixture to the chopped onion and chilli, mix together, and add the chopped coriander stalks.
4. Make the salsa by mixing the avocado, mango, chopped tomato, coriander and onion together. Season well and set aside at room temperature for the flavours to develop.
5. Mix the sour cream with the juice of 1 lime and the Tabasco, add a little salt and set aside ready to build to tacos when the prawns are cooked.
6. Preheat a char-grill or griddle pan until very hot.
7. Peel the large prawns and devein, but leave the heads on for a bit of a wow factor when serving.
8. Season the body of the prawns with plenty of salt. When the pan is up to temperature add the prawns to the pan. Cook until the prawns turn from grey to pink on one side, then turn to cook the other side.
9. When the prawns are cooked, remove from the pan and toss in the large bowl of marinade and arrange on a serving plate.
10. Season the rest of the tiger prawns and add to the preheated pan. Cook on the heat for around a minute each side until they have changed colour, from blue to pink. Remove to the large bowl of marinade. Toss together and prepare the tacos.
11. Briefly warm the tacos in a dry pan over heat, then start to put them together. First, add some lettuce, and 4 or 5 prawns from the marinade. Spoon over some guacamole, salsa, and finally the sour cream, top with fresh coriander.
12. Serve the tacos with the plate of head on large prawns with halved limes for squeezing.