While our standard vegetable nage is a very fine thing, and is used in many of our recipes, a vegetable stock can be taken a stage further by being made with baked vegetables. It gives a much richer, more robust flavour, and it’s excellent for making an excellent Slow Cooked Black Bean Soup

6 sprigs fresh flat-leaf parsley

6 sprigs fresh thyme

6 medium carrots, peeled cut into 2.5cm pieces

4 medium celery sticks, cut into 2.5 cm pieces

1 large onion, peeled and cut into 8 wedges

½ head of garlic (optional), peeled and lightly bashed

1 medium red onion, peeled and cut into 8 wedges

2 tbspns groundnut oil

2 large bay leaves

225 ml dry white wine

• Position a rack in the center of the oven and heat the oven to 220C

• In a large roasting pan, toss the herb sprigs, carrots, celery, garlic (if using) and onions with the oil and a few grinds of black pepper. Spread into a snug single layer. Roast, stirring twice, until the vegetables are tender and browned in spots, for about 40 minutes

• Transfer everything to a stock pan or large wok, add 2.8 litres cold water and the bay leaves, and bring to a boil. Turn the heat down and simmer gently, uncovered, for 30 minutes

• Add the wine and simmer for 20 to 30 until the broth is reduced to 1500ml and has a full vegetable flavour. Strain the broth through a fine-mesh sieve, pressing gently on the vegetables to extract as much liquid as possible. Discard the solids. Season well