Onion-Buttered Noodles

• 1 3/4 pounds yellow onions
• 6 tablespoons salted butter, at room temperature, divided

Kosher salt and freshly ground black pepper

• 8 ounces long pasta, such as fettuccine or pappardelle
• 1 to 2 garnishes (optional, see Author Notes)

1. Halve, peel, and thinly slice the onions. Mince just enough sliced onion to yield 2 tablespoons, then set that aside.
2. Add 2 tablespoons of butter to a large skillet over medium heat. Once melted, add the sliced onions. Generously season with salt and pepper. Cook until golden and jammy, 25 to 35 minutes, stirring often and lowering the heat as needed to avoid scorching; you can add a splash of water every so often if needed to deglaze if the onions threaten to burn. When they’re done, drop the heat to as low as possible to keep warm.
3. Meanwhile, fill a large pot with water and set over high heat to come to a boil. When the water is boiling, generously season with salt, then add the pasta. Cook according to the package instructions until al dente.
4. With the skillet still over low heat, use tongs or a slotted spoon to transfer the pasta to the skillet with the onions (and don’t drain that water). Add the minced onion, remaining 4 tablespoons of butter, and ¼ cup of pasta water, then toss everything together. Add more pasta water if needed to reach a sauce consistency you love, keeping in mind that it’ll thicken as it sits. Toss in or sprinkle with a bonus or two, if you’d like.