Preheat the oven to 180c.


In a medium saucepan of salted boiling water, blanch the zucchini and asparagus for 1 minute, then drain well and pat dry.

In a large bowl, beat the eggs with 1/2 teaspoon of salt and 
1/4 teaspoon of pepper. Stir in the vegetables. In a bowl, season the ricotta with salt and pepper.


In a 12-inch ovenproof nonstick fry pan, heat the oil. Add the egg-vegetable mixture and cook over moderately low heat, stirring occasionally, until starting to set at the edge, 3 minutes. Dot the ricotta on top.

Transfer the pan to the oven and bake for 20 to 25 minutes, until the frittata is just set. Let cool slightly, transfer to a platter, cut into wedges and serve.