1To prepare prawns so you separate the meat from the heads and shells save shells and meat (don’t cook). To prepare crayfish cook first; by boiling; put crayfish in a large pot then cover with water if live kill first by slicing through the head, then bring to the boil then simmer 5 min for the first 500 grams and extra 3 min for every other 500 grams then drain and cool and remove an edible white meat (claws legs tail …) keep shell, head and anything else that’s left.
2Put the shells of the prawns/crayfish in to the 500mls of water into a saucepan with the lemon/lime rind, lemon/lime juice, thyme, kaffir lime leaves, horopito or bay leaves, 1/2 tsp. salt and tsp. ground pepper. Bring to the boil and simmer till liquid has reduced by half.(the last two steps gan be done at any time the next steps need to be done when cooking for meal)
3Strain into a bowl then remove a cup and reduce by half in a sauce pan and set a side make sure it stays warm for the sauce. (save the rest bisque for the freezer)
4In a sauce produce a basic roux by melting butter then add some pepper+salt and the flour then fry off ready for thickening.
5Add the reduced bisque (it should be half a cup liquid) and milk slowly while continually whisking on medium heat once it has thickened and remove from the heat and continue whisking for another 1/2 minute.
6Cook pasta and drain, in bowl (or the pot you cooked the pasta in) mix the sauce and some fresh basil and the prawns (fried in some butter) or the crayfish meat shredded.
7Serve with some grated parmesan and basil with salt and pepper to taste.