Over the weekend at SF Chefs, I watched Italian stallion Cesare Casella (who flew in from New York for the occasion) demonstrate how to make the perfect pasta pomodoro. A native of Tuscany, Casella started by sautéing red onions and guanciale in a large pot. It seemed like there was nothing too special about his technique for cooking the classic Italian sauce, until he dumped the uncooked spaghetti into the bubbling tomato mixture!
In order for the pasta to really soak up the flavor of the tomatoes and aromatics, he recommends cooking it not in a pot of boiling water, but in the sauce itself. Thin the sauce with water and stir the pasta every now and then (like you would risotto) to ensure that it doesn't stick to the pan. Cook time for the spaghetti will take longer (about 15 minutes), but it's worth the effort. I tasted the finished pomodoro and it was amazing! Have you ever made pasta in the sauce rather than in boiling water?
Source: Flickr User citymama