Brrrrr..... let's make some soup!
We had a Japanese exchange student when I was a kid. She was fascinated by my blond hair and I was fascinated by her packages of just-add-water miso soup. It would be a decade before I heard the word "umami," but that's what I tasted in those packets. I liked the strange protein-y flavor of the broth and I liked how the toothsome re-hydrated seaweed slipped across my tongue. If you handed me some instant miso soup now, I would slurp it up and still be delighted by its exoticism.
The soups I make at home are less exotic, but no less satisfying. Soup is straightforward in theory. It's complexity lies in the execution... in how you build flavors and the first flavor layer can come from a mirepoix. Unlike "soup," "mirepoix" is fun to say and it's the colors of the Irish flag, which makes me like it even more.
According to Wikipedia, it's referred to as "The Holy Trinity" in Creole cooking and it IS that. A mirepoix is a combination of two parts chopped onions, one part chopped carrots and one part chopped celery sauted in some fat (butter, oil, bacon drippings, whale blubber). You don't have to stick to onions, celery and carrots, either. You can swap out the onions for leeks or shallots, or a combination. You can use fennel instead of (or in addition to) the celery. And there are all kinds of cool carrots in the farmers' market this time of year... might I recommend white ones for your mirepoix needs?
So put a healthy splash of olive oil and/or a pat of butter in a big Dutch oven and turn on the heat. Add your mirepoix. Stir over med-high heat until all the veggies are coated with the fat, sprinkle with salt and saute until they are limp/tender and are starting to get a little color. This is a good time to add a healthy amount of garlic. I buy jars of minced garlic at Trader Joes and I'm not embarrassed to admit it. If you have larger chunks of garlic (like chopped cloves), you can add them to the mirepoix sooner, but the minced stuff burns quickly, so I don't allow it too much saute time.
If you don't have a Dutch oven, maybe consider getting one. A Dutch oven is a wide, cast iron pot often coated with enamel. It's ideal for making soup because it distributes heat very evenly and the wider bottom gives you more surface area for sauteing. They are a little on the pricey side. BUT I was once getting my hair done in the home salon of my former hair cutting lady and while I was sitting under the hairdryer, she started making her dinner. She pulled out this lovely red Dutch oven and proceeded to use it to boil artichokes. I try not to be judgmental about how people prepare their food, but I was horrified that she was full-on boiling artichokes. To distract myself from that atrocity (or should I say "artichocity"), I asked where she got the great Dutch oven. She gave me a look and said "it's not an oven, it's just a pot from Out of the Closet." So should you find yourself at a thrift store, keep an eye out for a Dutch oven. And should you find yourself with artichokes, please steam or grill them.
Back to our soup. Your mirepoix is sufficiently sauteed, what next? This would be a good time to add some liquid and something that can stand to be cooked in liquid for a while. For the liquid... chicken stock, vegetable broth, some member of the broth/stock family. For the something that can stand to be cooked in liquid for a while... potatoes, squash, surprise me. Trader Joes sells pre-cooked lentils that are great for soup: add two packs of cooked lentils to your sauted mirepoix, pour in a box of chicken broth and you're nearly there.
For other kinds of soup, you could add a grain, like barley, cous cous (is that a grain), quinoa. I would start with 4-6 cups of liquid and 1-2 cups of potatoes or what have you. Bring to a boil, turn down the heat and simmer until your components are as soft as you want them and the soup has cooked down enough to concentrate the flavor a bit.
The final step in making soup is the "season to taste" step. Seasoning is basically alchemy. It's a science, but an inexact one. If you seasoned your mirepoix with salt and pepper, you are halfway there. If you wait to season until you have a giant pot of bubbling soup: good luck to you, friend. The more you have of something, the more seasoning it'll need and the harder it is to tell how much is enough. So season as you go. By the way, I like to use Kosher flake salt. You can buy giant boxes of it at various not-terribly-hard-to-find locations. I never use regular table salt, because I think it tastes metallic (probably because it's iodized) and I rarely use anything fancier than Kosher flake salt.
Everything needs salt and pepper, that's old hat. But everything also needs some acid. Acid (lemon juice, vinegar) literally makes your mouth water and that makes your food taste better. Squeeze a lemon or a lime or a grapefruit over your soup, or add some white wine vinegar or apple cider vinegar. Depending on what you're making, a robust vinegar like balsamic or red wine might be overpowering, but it might not.
Some other seasonings to experiment with: hot sauce, fish sauce, beer, red or white wine, tomato paste, Worcestershire sauce, toasted sesame oil, soy sauce, mustard powder, cayenne pepper, nutmeg, curry powder, Chinese five spice powder, Arab seven spice powder... that's basically a tour of my seasoning shelf. You can add fresh or dried herbs almost anywhere along the way. Surprisingly, you should use half as much dried herbs as fresh. You'd think fresh herbs are stronger, but you would be wrong... this is a strange world we live in.
For the lentil soup I outlined above: follow the broth with half a cup of soy sauce and a scant (or not, if you're feeling generous) cup of red wine. This lentil soup is really a great, fast meal, especially if you microwave your chicken broth or heat it on the stove while the mirepoix is sauteing. Because the lentils are already cooked, you can just dump everything else on top of the sauted mirepoix, bring the soup to a boil, simmer for ten minutes and then serve (maybe topped with crumbled bacon). Having hot broth to add to the sauted mirepoix cuts down on the amount of time it takes to bring the soup up to a boil. I made this camping once and it was a big hit--I brought olive oil, salt, pepper, packets of pre-cooked lentils, boxes of broth and pre-chopped mirepoix in a plastic bag, put my Dutch oven over the fire and went to town--although, everything does taste better when you're camping.
If you want a thicker soup, you can stir in some butter, cheese or creme fraiche at the end of cooking. Or you can scoop a few cups of soup out of the pot and blend it either in a blender or with an immersion blender and then stir it back into the soup. Unless you like huge messes, I wouldn't recommend blending soup in a food processor.