Step 1:
1) While the pasta boils, fry chorizo in a little butter/olive oil mix(so the butter doesn’t burn) over a medium/highish heat. Step 2:
2) Once it’s leaked a bit of fat(and lovely spices) cook the prawns. Step 3:
3) Add a bit of creme fraiche (not to much it’s just a vehicle for the chorizo flavor) and season. Step 4:
4) Drain cooked pasta (throughly, maybe even deliberately rough it up a bit so the sauce sticks) then mix into to the sauce, then season again (fresh ground pepper, has to be). Step 6:
Done. Easy, but outstanding. N.B. Might find before you add the pasta that the sauce seems to be splitting but with the carbs of the pasta tends to bind up ok. 