Caramelised onion, squash & gruyère tart
Take your time caramelising the onions for this dish – cooked slowly over about 20 minutes, they’ll soften and become jammy and sweet. They’re the star of this tart, also punctuated by golden, tender cubes of squash.
SERVES 8-10 PREP 30 mins plus chilling COOK 1 hr 30 mins MORE EFFORT
3 tbsp rapeseed or olive oil3 onions, halved and finely sliced3 tbsp red wine vinegar1 tbsp sugar400g butternut squash (about ½), peeled and deseeded8 thyme sprigs, leaves picked1 tbsp Dijon mustard4 eggs75ml double cream75g gruyère, grated
