Preheat the oven to 180C/350F/Gas 4 - 200C/400F/Gas 6.
Quickly blanch or just plunge the peas into boiling water to soften or if small and sweet just wash. Place in a pestle and mortar with roughly chopped mint (reserving a few leaves for garnishing) and grated pecorino and pound to a paste. Add some salt, a little parmesan cheese, a squeeze of lemon juice and the olive oil.
Melt the butter in a non-stick, ovenproof frying pan. Break the eggs into a bowl, mix lightly, add a splash of water and season. Add the mixture to the pan and then fold in some of the pea mix, stirring once or twice.
Place the crème fraîche in the middle and bake in the oven for 3 minutes. Slide onto a plate and serve sprinkled with the reserved mint and the remaining parmesan.