Step 1

Heat oven to 200C/180C fan/gas Put the butternut squash in a bowl, cover with cling film and cook in the microwave on High for 5-7 mins until tender. Meanwhile, line 8 holes of a muffin tin with squares of baking parchment – allow a little overhang at the top as the frittatinis will puff up.

Step 2

Divide the squash, peas and feta between the lined muffin holes – they should be quite full. Beat the eggs in a jug with some seasoning, then pour into the muffin holes. Put the tin in the centre of the oven and bake for 20 mins. Leave to cool for about 15 mins before packing into a cooler bag for transporting, or chill for up to 24 hrs.