Prepare the barbecue for direct cooking over medium-high heat (200°C to 230°C).

After the crayfish have been put to sleep, use a large, sharp knife or cleaver to cut the crayfish in half lengthways, through its head and tail. Scoop out the yellow/brown tomalley and remove the intestinal vein. Lightly coat the flesh with olive oil and season with salt and pepper. Cut the lemon in half.

Add the chorizo and garlic to a Weber Ware Frying Pan. Place the frying pan on the cooking grill over direct medium-high heat, close the lid, and cook until the chorizo is starting to caramelise and the garlic is cooked, 4 to 5 minutes, stirring as needed. Remove the frying pan from the barbecue and stir in the butter and oregano, leaving the butter to melt.

Place the crayfish halves on the cooking grill, flesh side down, and grill over direct medium-high heat, with the lid closed, until seared, about 3 minutes. At the same time, add the lemon halves to the barbecue, cut side down, and grill until caramelised, about 3 minutes. Set aside until required. Flip the crayfish halves onto the shell side. Carefully spoon half of the chorizo butter over the crayfish, close the lid, and cook until the crayfish is just cooked through, a further 3 to 5 minutes.

Serve the crayfish immediately with extra chorizo butter and a generous squeeze of caramelised lemon juice.