Carrot and Red Onion Frittata recipe

Give the oven at least 10 minutes to fully come up to temperature so the frittata starts cooking immediately when it goes in. An oven that is still heating can leave the centre wet while the top colours too quickly.

Aim for even, thin strands of carrot and onion slices of similar thickness so they soften at the same pace. If the carrot is grated too coarsely, it can stay a little crunchy in the finished frittata.

Keep the heat at medium rather than high so the vegetables sweat and soften without taking on much colour. Stir occasionally and lower the heat if the margarine starts browning or the onion edges catch.

Whisk until the eggs look uniformly pale yellow and slightly frothy, with no visible streaks of white. Adding the cheese at this stage helps it disperse evenly instead of sinking to the bottom.

Tilt the pan so the egg flows into the gaps between the vegetables, then use a spatula to level the surface. The edges should look just starting to turn opaque while the centre is still loose and glossy.

Bake on the middle shelf so the top cooks evenly without over-browning. Remove it when the centre still has the faintest wobble, as it will finish setting from the residual heat.

Let it rest in the pan before cutting so the custard firms up and the slices hold together cleanly. Wiping the knife between slices gives neater wedges and stops the filling dragging.