Step 1

Preheat oven to 200degC

Step 2

To cook caramelised onions, heat olive oil in a large fry pan on medium heat. Cook onions for about 10 minutes whilst stirring frequently until soft and golden brown. If at any time they are catching on the bottom of the pan and burning, just add 1-2 tablespoons of water, stir, and they should lift. Add brown sugar and balsamic vinegar, and continue cooking for a further 2-3 minutes. Turn off heat and season to taste with salt and freshly cracked black pepper.

Step 3

To make tarts, cut puff pastry into quarters, so you have 4 smaller squares and place on a baking tray. Use the back of a blunt knife to gently mark a narrow 0.5cm border inside each piece of pastry. Spread caramelised onions on pastry, roughly keeping within the border. Top with chunks of leftover roast vegetables, sprinkle over thyme (if using), and chunks of leftover cheese.

Step 4

Bake for about 15 minutes or until pastry is puffed and golden. Garnish with parsley, and serve with tomato chutney or relish, and a big leafy green salad on the side.