Spaghetti With Onion and Tomato Sauce

• 2 tablespoons unsalted butter
• 1 medium red onion, thinly sliced
• 2 cups canned italian plum tomatoes with their juice, pureed in a food processor
• 2 tablespoons kosher salt
• 1 teaspoon kosher salt
• 1 lb spaghetti or 1 lb linguine
• 14 cup freshly grated parmigiano-reggiano cheese
• 1 tablespoon extra virgin olive oil

1. Add butter to a large skillet over medium heat.
2. Add in onion and cook, stirring frequently, until soft, about 5 minutes.
3. Add the tomatoes and 1 teaspoon salt; when the mixture starts to bubble, decrease heat to very low and cook at a bare simmer for 5 minutes; remove from heat and set aside.
4. While the sauce is cooking, fill a 10-quart stockpot with 7 quarts water and bring to a boil over high heat.
5. Add the remaining 2 tablespoons salt; add the pasta and stir; cook until al dente.
6. Reserve 1/2 cup of pasta cooking water, and drain the pasta.
7. Add the pasta to the skillet with the sauce.
8. If the pasta looks dry, add the reserved cooking water 1 tablespoon at a time, tossing to combine between additions.
9. While still tossing the pasta and sauce, slowly sprinkle on the cheese and toss until all the cheese is incorporated.
10. The dish should look creamy and moist.
11. Serve immediately, drizzling each portion with a little bit of olive oil.

unsalted butter, red onion, italian plum tomatoes, kosher salt, kosher salt, linguine, cheese, extra virgin olive oil

Taken from www.food.com/recipe/spaghetti-with-onion-and-tomato-sauce-441874 (may not work)