Use new season's potatoes and asparagus to make this Italian-style omelette and serve it for a light lunch or supper with salad.
The trick for a perfect frittata is to cook over a medium to low heat and allow the mixture to set slowly without stirring. Stirring once the egg has begun to set will break the mixture apart. Too high a heat will burn the base before the egg is set sufficiently to finish under the grill.
Parmesan cheese is not truly vegetarian, as it contains animal rennet. To make this dish 100% vegetarian, omit the cheese or find a suitable vegetarian substitute made without animal rennet. In supermarkets look for the 'parmesan style hard cheeses' which are suitable for vegetarians.
Be sure to use freshly grated Parmesan. It is quite expensive but you don't need to use a lot and the flavour is infinitely superior to ready-grated Parmesan in tubs. * For a vegetarian frittata, use an alternative, strong-flavoured cheese.
I only used about half the amount of asparagus as the recipe called for (and it was plenty) and bumped the eggs up to 8 as I needed to serve 5 people. I also used pecorino-romano in place of the parmesan. Tasty frittata. I'd add some onion next time. - 19 Feb 2015