When I cooked squash and potato soup in the past, I went by a 1:2 ratio, that is, one part squash for two parts of potatoes. Like, if I had a quarter of a kilo of squash that means half a kilo of potatoes should go with it. The rationale behind the 1:2 ratio was the potato starch. I like my squash soup to be thick so I used more potatoes. The drawback, of course, was that the soup was paler than I’d like and the flavor and sweetness of the squash was not that pronounced.
A few days ago, I decided on a different technique equal amounts of squash and potatoes and less broth. It worked. It was more of a squash soup rather than a potato soup. To make the very thick soup even more filling, I added sliced chicken breast meat (I boiled two chicken breasts to make the broth) and croutons and topped it all with grated cheese before serving. My family loved it.
Boil, broil or steam the chicken breasts. Cool, debone and cut the meat into thin slices. Cut off the skin of the squash, scoop out the seeds and cut the flesh into fairly small pieces, about 1-inch cubes, for faster cooking. Peel the potatoes and cut similarly.
Melt the butter in a small pan. Over low heat, cook the onion until soft. This takes about 10 minutes with occasional stirring. I know that 10 minutes might sound like a long time to spend on an onion but, believe me, it’s worth the trouble. When the onion is soft, turn off the heat. While the onion sweats in the pan, in a large pot, heat the chicken broth. Add the squash and potatoes, cover and simmer until they turn mushy. This will take anywhere from 15 to 25 minutes depending on how young or mature your vegetables are.
When the squash and potatoes are done, scoop them out with a slotted spoon and place in the blender or food processor (you can also mash them with a fork). Add about 2 cups of broth and the onion with the butter. Process until smooth. Pour the pureed vegetables back into the pot of broth. Season with salt and pepper. Reheat until bubbly.