Lighter prawn cocktail with avocado

Ingredients

• 500g/1lb 2oz frozen Atlantic prawns, de-frosted, drained
• 150ml/5fl oz ready-made gazpacho
• 150ml/5fl oz low-fat crème fraîche
• 1 shallot, peeled, very finely diced
• 2 tomatoes, skins removed, flesh diced
• 1 red chilli, stalk removed, finely diced
• 6 radishes, trimmed, finely sliced
• small bunch fresh coriander leaves, chopped, plus extra sprigs to garnish
• 1 lime, juice and zest
• 8 dashes Tabasco
• salt
• freshly ground black pepper
• 2 small baby gem lettuces, shredded
• 1 large ripe avocado, peeled, stone removed, flesh sliced lengthways
• 4 pinches cayenne pepper
• 4 large fresh cooked prawns, heads and shells intact
• 4 sprigs fresh coriander