Michel Roux’s vegetable tart tatin

3 small heads of red chicory

3 small heads of yellow chicory

200g slender carrots,

halved lengthways

300g kohlrabi, cut into batons

100g cauliflower florets or sprouting broccoli, halved

1 large onion, cut into wedges

2tbsp olive oil

2tbsp butter

2tbsp caster sugar

1 red chilli, deseeded and sliced

Leaves from 1 thyme sprig

350g puff pastry

Flour, for dusting

Salt and black pepper