We put the spaghetti in a pot with boiling salted water for the time recommended by the manufacturer for them to be al dente. We drain and reserve them. Chop the onion as well as the pepper and chilli, removing the seeds.
Heat a tablespoon of olive oil in a large frying pan and sauté the onion for about three minutes. Add the pepper and stir. We cut the chili into slices that we add to the above with the chilli.
We leave in the fire, low, for about five more minutes. Finally we add the prawns, the cumin, salt and pepper. We stir and leave on the fire, at medium intensity for about 10 to 12 minutes. To finish we add the spaghetti, adjust the seasoning and leave about three to four minutes over medium heat.