The one that I made recently was a vegetable and bean soup, but all of them start out with potato (preferably sweet potato) and some type of onion. I really like using leeks because of their delicate taste. The most important thing to remember about leeks is that they grow in sandy soil and that you have to clean them thoroughly. I normally dice them by cutting the leek in half, getting rid of the rough tops and cutting into half moons. I then get a bowl and fill it with water, dump in the leeks, move around and clean them and then lift them off the top and the dirt goes to the bottom of the bowl. I leave the skin on my sweet potatoes when I dice them. I like a rustic looking soup so aesthetically I don't mind skins and more so the nutrients are rich in the skin of the potato and I want to get all of that nutrient content. I saute the potatoes and leeks (normally 2 leeks to 2-3 sweet potatoes) together in a bit of extra virgin olive oil, salt, white pepper, cumin and garlic. I add a bit of water or broth as the mixture dries out and slowly the vegetables break down.
When the mixture has cooked enough to become a thick paste I add the other vegetables that need a lot of cooking time. Usually for me that is the carrots and celery. I follow this step by adding 4-8 cups of broth depending on how many servings you want to stretch out of the pot of soup. Look for reduced sodium quality broths. Don't forget to check seasoning along the way to make sure that all the liquid doesn't make the soup bland. I normally wait about 20 minutes after the broth has come up to a bubble and had time to reduce a bit. I wait a bit to add things like zucchini and the very end to add frozen vegetables like peas, corn and spinach right before serving. I also don't add the beans too early because when I stir the soup I don't want the beans falling apart. When adding lentils do so when you add all the broth. Make sure to rinse lentils and beans. I use canned beans because I don't have time to soak them overnight and then cook them for hours. I have done it and it does taste good, but not good enough to ignore the convenience and value of canned beans.
I finish the soup with fresh herbs, a squeeze of lemon and some fresh salt and pepper to taste. It is a delicious meal any time of day, any time of year. Any vegetable in the fridge or freezer can be used and it is a good way to use up vegetables that might be a tad past their prime. When stewing for upwards of an hour (really a soup is done when you think it is done - always taste test!) imperfections are less noticeable.