1- Trim the artichokes, remove the stalks, the toughest external leaves and the tips; cut them into half, remove any fibres inside, cut into thin wedges and place in cold water with lemon juice to prevent them from turning black. Blanch the tomatoes in boiling water, drain, remove the skin and seeds and dice the pulp. Wash the parsley, dry and chop; peel the onion and chop.
2- Put the oil in a pan and soften the chopped onion; add the drained artichokes and peas and cook for 5-6 minutes; add the diced tomato, season with salt and pepper, cover and continue to cook for a further 7-8 minutes on a medium heat and sprinkle with the chopped parsley.
3- In the meantime cook the elicoidali until they are "al dente"; drain, add the artichoke and pea sauce, sprinkle with grated Parmesan cheese and serve hot.