Using homemade chicken stock will always improve your dishes, but when you are short of time, a low-sodium canned stock can be used. Making your own chicken stock is easy, however, when you have both the time and a whole chicken for another use. For the stock, I typically use only the carcass of the chicken and a single additional breast. I have also used the carcass of a roasted chicken with good results.
Place the chicken carcass and chicken breast in a large stockpot and add water to cover by about 2 inches. Bring to a gentle boil over high heat, using a slotted spoon to skim off any foam that forms on the surface. Add the carrots, leeks, turnip, and parsley, decrease the heat to medium-low, cover partially, and simmer gently, skimming as needed, for about 2 ½ hours, or until the liquid is reduced by almost half.
Strain the stock through a fine-mesh sieve into a clean vessel. If using immediately, skim off as much fat as possible from the surface with a large spoon. Season the stock to taste with salt. If storing for later use, prepare an ice bath in your sink, pour the stock into a tall container, and place it in the ice water to cool quickly. Stir the stock periodically to help reduce the cooling time, minimizing the opportunity for bacteria to grow.
When the stock is at room temperature, cover and place in the refrigerator until well chilled. Remove from the refrigerator and lift off and discard the layer of fat that has solidified on top. Re-cover and refrigerate for up to 3 days or freeze for up to 6 months.
Sopa de picadillo: I never tire of eating this simple delight. When I am preparing stock specifically for this soup, I usually reserve a chicken breast to simmer, shred, and add to the pot. If you are using homemade frozen stock or store-bought stock, it is fine to omit the chicken breast.