Nothing improves the taste of soups, stews or sauces more than a good home-made stock. You get a depth of flavour and unctuousness that stock cubes just cannot provide.
I suggest using 1 chicken carcass but you could also use leftover chicken bones from a roast dinner, chicken wings, or whatever else you can get your hands on. You can never really have too much meat or bones in your stock.
Top and tail your vegetables, peel your carrots (leave the skin on the onion), and chop into chunks. Throw them into a big pan with herbs and chicken bones. Cover with water and bring to the boil. Reduce the heat to a simmer and cover with a lid. Simmer for at least 3 hours. If you have a pressure cooker, cook the stock under pressure for 1 hour.
Remove the stock from the heat and let it cool down a bit. Then strain it through a colander into another pan. On high heat, reduce the stock by about half. Taste it for seasoning and add salt if required.
TIP: when seasoning something like this, remove a cupful of stock from the pan. Add small amounts of salt to the stock, and taste it after each addition of salt. When the stock is too salty, add back the cupful and your stock should be perfectly seasoned.
Put the stock into a fresh container and place it in the freezer for about an hour, or the fridge overnight. The fat in the stock will have floated to the top and set. Skim this off and discard or save for other uses.
The stock is now ready. It will keep for about a week in the fridge, or three months in the freezer.