Bring a pan of water to the boil and tip in the pasta. Cook for 10 mins until tender, then add the petit pois and cook for a further 2 mins.
Drain the pasta and peas, then run under cold water until cooled. Drain well, then stir through the crème fraîche.
Transfer portions to little plastic containers for easy transportation. Pack with a few lemon wedges to squeeze over just before eating.