Heat oven to 220C/200C fan/gas 7.
Put the squash, onions and chilli flakes
in an ovenproof pie dish (or 4 individual
dishes). Season and cook for 20 mins
until the squash is tender and the onions
are starting to char at the edges.
Meanwhile, put the spinach in a
colander and pour over a kettleful of
boiling water. Squeeze out any excess
liquid and stir into the squash mix. Dot
over the feta, crumple up the pastry and
place on top, then brush with the oil.
Return to the oven and cook for a further
15 mins until the pastry is golden and
crisp. Serve with a green salad, if you like.