Umido Di Cipolla (Pasta With Onions And Tomato)

• For the condiment
• 2 1/2 pounds white onions, very thinly sliced
• 3 tablespoons unsalted butter
• 4 tablespoons extra-virgin olive oil, preferably lightly fruity
• 2/3 cup tomato puree
• 1/2 teaspoon salt
• Freshly ground black pepper
• To make the dish
• 1 pound pasta, almost any kind except pastina or angel hair
• 3/4 cup grated Parmigiano-reggiano

1. Put the onions in a large pan, preferably terra cotta, with the butter and oil. Saute over medium heat for about 20 minutes, stirring from time to time, until quite soft, being careful not to let them brown beyond a golden beige.
2. Add 1/2 cup (100 milliliters) water, let it evaporate somewhat, then add the tomato puree and cook over very low heat, stirring occasionally, until the onions have practically turned to mush, about 50 to 60 minutes. Add the salt and a few grindings of pepper.
3. Bring 5 quarts of water to a boil in an 8-quart pot over high heat. Add 3 tablespoons kosher salt, then add the pasta and cook, stirring occasionally, until very al dente. Reserve a ladleful of the water.
4. Drain the pasta and add it to the onions. Stir in 2 to 3 tablespoons of the reserved pasta water and the cheese. Toss over low heat until the pasta has absorbed the liquid.
5. Warm a serving bowl or platter in a low oven. If using the oven is not practical, warm the bowl just before use with hot water, or even a ladleful of the pasta-cooking water. Transfer the pasta to the heated bowl and toss with the sauce. Serve immediately.

condiment, white onions, unsalted butter, extravirgin olive oil, tomato puruee, salt, freshly ground black pepper, pasta

Taken from food52.com/recipes/27324-umido-di-cipolla-pasta-with-onions-and-tomato (may not work)