There's no better and simpler way to cook a bunch of vegetables, and it's highly flexible – adapt quantities to what you have on hand, throw in sliced carrots, or diced roots... It'll never be exactly the same twice, especially if you change the spices. When you first put the chopped vegetables in, it'll look like an enormous mound of them, but as they cook (and low temperature is essential) they release their juices and settle down into a stew. This is also why no water is added at any point. There's plenty in the ingredients already!