Place the basil, butter and lemon zest in a small food processor. Season with salt and pepper and process until smooth and basil is finely chopped.

Preheat barbecue or grill plate over high heat.

Brush prawns with olive oil and season with salt and pepper. Place the prawns flesh side down and grill for 1-2 minutes each side or until just cooked. Set aside, keep warm.

Heat oil in a large deep sided frying pan.

Add the onion and garlic, cook stirring for 6-8 minutes or until soft and golden.

Add the chilli, thyme, lemon zest, white wine and cream bring to the boil.

Add the mussels reduce heat and simmer for 3-4 minutes or until mussels have opened.

Add the prawns to the pan and warm through, basting with the broth.

Serve with large wedges of toasted sourdough smothered with basil butter and fresh lemon.