Peel and dice the butternut squash into 2cm cubes.
Heat the oil on a non-stick frying pan and gently sauté the squash for about 10 minutes under cover.
Meanwhile cut the halloumi into 2cm cubes. Deseed and finely chop the chilli. Finely chop the garlic.
When the squash is tender add the halloumi, chilli and garlic. Stir for a couple of minutes.
Lightly whisk the eggs with a couple of pinches of salt. Add the chopped herbs.
When the halloumi & squash start to brown, pour this mixture over them. Cook for 5 minutes, until the base is set.
Turn on the grill in the oven. Brown the top of frittata for 5 mins until puffed up and golden. Serve warm or let it cool and cut into wedges or squares.