Cook potatoes in a saucepan for about 7 minutes or until the potatoes are tender but not mushy

Add in the peas and cook until barely tender, about 2 minutes. Drain and set aside to cool slightly

Heat 1 tablespoon of oil in an oven proof 20cm frying pan (9 inch skillet) over medium heat. Add the onion and cook until softened, but not browned, about 8 minutes. Add the saffron and cook until aromatic, about 1 minute. Set aside to cool.

Beat the eggs with a 1/2 teaspoon of salt and some freshly ground black pepper. Mix in the peas, potatoes, prosciutto and the onion mixture. Wipe the frying pan clean

Move an oven rack to the top position and heat the grill (broiler)

Heat the remaining tablespoon of oil in the cleaned frying pan over medium heat. Once the pan is hot add in the egg mixture and cook, occasionally sliding a spatula around the edges of the pan to loosen the omelette. Cook until the bottom/sides of the omelet are golden (the eggs are still runny just on the top), about 8 minutes

Place the pan under the pre-heated grill and cook until just golden brown on top and set 3 – 5 minutes

Allow to cool. The omelette can be cooled to room temperature or even chilled for several hours if desired

Cut the omelette into wedges or into 1 inch squares to serve