Put the lemon juice, garlic, chilli and 2 tablespoons of the oil in a non-metallic bowl. Add the swordfish cubes and turn to coat in the marinade. Cover and leave to marinate in a cool place for 15 minutes.
Cook the pasta in a large saucepan of salted boiling water according to the packet instructions until al dente.
Meanwhile, heat the remaining oil in a large frying pan over a high heat. Cut the artichokes in half, add to the pan with the olives and cook, stirring, for 2 minutes. Season the swordfish with salt and add to the pan with the marinade. Cook for 2–3 minutes, stirring occasionally, until the fish is just cooked.
Drain the pasta, reserving a ladleful of the cooking water. Stir into the frying pan and add the mint. Toss well over a low heat and pour in the reserved pasta cooking water. Continue stirring until the pasta is well coated and looks silky. Serve immediately.