Half-fill a large frying pan with water and bring to the boil. Add the asparagus and cook for 4–5 minutes until the spears are just tender. Lift them out with tongs or a slotted spoon, transfer to a board and leave until they are cool enough to handle.
Bring the water in the pan back to the boil. Add the peas and pasta, bring back to the boil again then cook for 5 minutes or until tender.
Meanwhile, beat the eggs in a large bowl. Cut the tips off the asparagus and set them aside. Slice the asparagus stalks and add to the eggs together with the spring onions and mint. Drain the pasta and peas and immediately stir them into the egg mixture.
Preheat the grill to high. Dry the frying pan then heat the oil over a medium heat. Pour in the egg mixture, making sure all the ingredients are evenly distributed. Reduce the heat slightly and cook for about 5 minutes until the omelette is two-thirds set, but still moist on top, and browned underneath.
Sprinkle the cheese over the frittata and place under the grill. Cook for about 5 minutes to brown the top. Cut into four large wedges and serve garnished with the reserved asparagus tips.