Preparation

• Heat the olive oil in a large skillet over medium-high heat and add the onions. Decrease the heat to medium-low and cook, stirring frequently and seasoning with salt to taste as you go, until the onions are soft and golden brown, 20 to 30 minutes.
• Meanwhile, fill a large pot with water and bring to a boil. As the water heats, add enough salt so that you can taste it. Add the pasta and cook until soft, just past al dente. Drain the pasta, reserving 1/2 cup of the pasta water. Combine the yogurt with 1/4 cup cooking water and mix well. Add more of the reserved pasta water as needed to get the sauce to your desired thickness. Toss the pasta with the yogurt mixture. Serve the pasta immediately, sprinkled generously with cheese and topped with the caramelized onions and their juices.

There are endless ways you can fancy up this meal. Throw in spinach or chard as the pasta finishes boiling. Or blend the sauce with peas, mint, or tahini.