Vegetables don’t give stock the slightly thick, gelatinous quality that meat or fish bones do. The vegetable stock will remain well-flavoured but thin and watery. If you make judicious use of commercial bouillon powder or cubes you might have better results but be careful because often they are excessively salty. Look for a top-quality product and use it in exactly the proportions given. Bring the stock to a boil along with chopped vegetables like onion, celery, carrot, and leek. Don’t crumble stock cubes directly into a soup, the taste will be too sharp.