My Dad often used to say "Finish your dinner or we'll have it for soup for tomorrow". You see, soup can be made from pretty much anything.
Following are some easy (short cuts) recipes:
Today, if you have ready made chicken or beef stock on the shelf, you're one third of the way there. The other third is what they call a 'Mirepoix', which is a fancy name for a base of minced (yellow) onion, grated carrot and thinly chopped celery.
Mixed Vegetable Soup: Sautee the 'mirepoix' in a little bit of oil or butter until shiny and soft, add four or more cups of broth, a chopped tomato or two, a few mixed (fresh, canned or frozen) vegetables (string beans, squash, spinach leaves, turnips, potatoes, more (cut) carrots.....some fresh (chopped) parsley and you can even add some noodles. Bring everything to a boil, lower the heat to a medium simmer and cover for about 20 minutes. Presto! You'll have a delicious vegetable soup.
Bean Soups: Add minced garlic, bacon, ham or crumbled sausage to the mirepoix and sautee throroughly. Add canned, cooked or leftover beans (lentils, garbanzos i.e. chick peas, dried peas) of your choice (drain and rinse optional) and add /or replenish bean liquid with water or broth (about 1 or 2 cups). Add flavors (cumin, parsely, rosemary or cilantro) then season with salt and pepper to taste. Bring to a boil, then cover and cook for about 20 minutes (cooking time is for already precooked legumes only.) Uncover and continue cooking at low heat until soup has the desired consistency
Potato soup: Prepare a mirepoix, then add chicken broth and leftover mashed potatoes. Blend with a hand mixer, reheat and garnish with cut scallions or chives. Serve with croutons.
Have fun!