Mate I find the tropical crays are a bit tough so they go better in something rather than just straight boiling which is all the southern crays need.
Thermodore is always a winner and pretty easy. Slice cray in half lengthways, scoop out meat, mix with a white sauce, place back in the shell and top with cheese. About 15 minutes at 180C should do the trick. That is the bush recipie off the top of my head. google will give you plenty of recipies with more specifics.
Another one is fry up some garlic and chilli in a few spoonfulls of olive oil for a minute or 2. drop in the cray meat (cut into bite size bits) and stir fry until pink/orange- bout 5 minutes. Throw that into some spaghetti with some roasted grape tomatoes and some basil and a bit more oil and your done.