Snap the ends off the asparagus where they naturally break to remove any woody ends. Cut the rest of the asparagus into approximately 1 inch pieces.

Peel and finely chop the onion/shallot.

Crack the eggs into a medium bowl and whisk them until the white is broken up and they are lightly fluffy. Add the cheese and salt and pepper to taste. Mix until combined.

Warm 1 tablespoon of oil in an 8 inch oven safe skillet over a medium heat. Add the asparagus and onion and cook for a couple minutes until the onion becomes translucent and the asparagus is tender to a knife-point.

Tip the asparagus and onions into the eggs and mix through. Add the remaining oil to the skillet, reduce the heat slightly and tip the egg mixture into the skillet. Spread the asparagus out evenly, as needed, so the pieces are evenly distributed across the skillet and not sticking out from the eggs.

Cook for around 5 minutes until the edges are starting to cook but the inside is still runny.

As it is cooking, warm the broiler. Put the frittata under the broiler to finish cooking the top, keeping a close eye on it so it doesn't cook too much. You want it to be set but not get too brown.

Serve warm or room temperature.