Finely grate the parmesan. Peel and finely chop the garlic.
Wash and thinly slice the courgettes. Wash the spring onions and cut into thin rings.
Cook the pasta in a pan of boiling salted water according to the pack instructions.
Meanwhile, heat the oil in a large non-stick pan. Add the courgettes, garlic and onions and fry over a medium heat for 4-5 minutes until softened.
Separate the eggs and place the yolks in a bowl (use the egg whites in another recipe). Add the creme fraîche, salt, pepper and stir with a whisk.
Drain the pasta, reserving 50ml of the cooking water. Mix the pasta water with the egg yolk mixture and add to the courgettes in the pan. Cook for another 1-2 minutes.
Toss together the courgettes and pasta. Scatter with the grated Parmesan and serve.