This grew out of a desire to do something with potatoes beyond regular standbys — I’d used potatoes in soup plenty of times, but this one was new to me and I’d been fortunate to have some onions to hand as well. As is my wont, I turned the recipe into a strictly vegetarian one, so substitute a rich vegetable broth for the beef one below, while margarine can stand in for butter. Vegetable oil is required but no one sort is specified; I chose canola rather than olive, say, figuring it would be lighter in the end. And indeed, the end result is hearty but not heavy, and there was plenty left over currently chilling in the freezer. I’ve no doubt this would go excellently with fresh bread to mop up the remains.
The basics of the recipe are below rather than reproducing her language word for word:
1 1/2 pounds yellow onions, peeled and thinly sliced
3 tbps. butter
3 tbps. vegetable oil
Salt if desired
2 pounds boiling potatoes, peeled and diced
3 1/2 cups meat broth
3 tpbs. freshly grated Parmesan
* Cook the onions, butter and oil (plus salt if desired) in an uncovered skillet over low to medium heat — the goal is to slowly wilt the onions, not deep fry them or the like. Cook until onions are light brown, then remove from heat but keep in the skillet.
* Boil the potatoes in 3 cups of the broth until tender — boiling should be steady, not maxed out. Hazan suggests salt here if desired but if you’ve already added some to the onions, then no need for more.
* Add the onions and cooking fat to the potatoes and broth mixture, using a bit of the broth to loosen up anything on the skillet.
* Add remaining broth and return to a gentle boil. Mash up some (not all!) of the potatoes with a wooden spoon against the side of the pot and then stir into the soup. Cook for 8 to 10 more minutes, adding more broth or water as needed.
* Stir in the Parmesan and serve out. I added more grated Parmesan on top plus ground pepper.