Real Vegetable Stock

Preheat oven to 200 C / Gas 6.

Cut the top off the head of garlic. Arrange the garlic, carrots, celery, onions, pepper and tomato on a large baking tray in a single layer. Drizzle the olive oil over the vegetables; season with salt and pepper.

Roast the vegetables in the preheated oven, turning every 20 minutes, until tender and browned, about 1 hour.

Combine the water, thyme, parsley and bay leaves in a large stock pot over medium-high heat. Squeeze the head of garlic into the stock pot and discard the outer husk. Place the carrots, celery, onions, pepper and tomato in the stock pot. Bring the water to the boil; reduce heat to low and simmer for 1 1/2 hours; strain and cool.