6: Pour 2 tablespoons olive oil into a large pan on medium heat. When hot, add the chopped onion, salt, pepper and cook without colouring for 3 minutes.
7: Add the carrot, leek and garlic. Mix well. Cook uncovered for 5 minutes on low heat.
8: Add 1 litre 500 ml water and the bouquet garni.
9: Cook on low heat for about 15 minutes.
10: After this time, strain the stock.
11: Leave to cool then transfer to a bottle or jar with a lid.
Remarks
You can vary the vegetables, but I advise you to keep at least carrot, onion and leek. If you want to freeze the stock, you can use an ice cube tray to make cubes: easy to take out exactly the amount you need.