Preparation
Preheat oven to 375F and place rack in the middle of the oven. Bring a large pot of water to a boil for pasta, salt water and cook pasta to al dente.
While the pasta water comes to a boil, place a medium pot over medium-low heat with 2 turns of the pan of EVOO, about 2 tablespoons, and the butter. Add the onion and garlic to the pan and cook the veggies until very soft, about 10 minutes.

