Omelets are a leftovers lover's best friend ... There is usually some frozen duxelles — chopped and cooked mushrooms — too, and this goes well with bland ingredients like cooked chicken ...

Add the frozen peas and cook for 1–2 minutes ... Spoon the bacon and pea filling down the centre of the omelette, sprinkle over half of the Parmesan and cook, without stirring, for a minute.