Cook the pasta according to the package instructions.
Meanwhile, skin then chop the chorizo.
Heat 1 Tbsp oil in frying pan. When it begins to brown and releases its fat, add the crayfish and the peas. Cook for 3-5 minutes, until the peas are tender and crayfish has warmed through.
Drain the pasta, reserving about half a cupful of the cooking water.
Toss the paste with the chorizo-crayfish mixture, add remaining olive oil and some cooking water (it should be moist). Stir in some chilli flakes then season with salt & pepper.
Serve immediately.