Joe Truex’ Spaghetti with Scallion Sauce

Prepare pasta according to package directions. Set aside 1/4 cup pasta cooking water. Drain pasta and return to pot.
While pasta is cooking, heat 3 tablespoons olive oil in a large skillet until hot but not smoking. Add scallions and garlic and sauté until scallions are softened, about 5 minutes.
Transfer half the cooked scallions to a blender and add zest, salt, pepper, remaining olive oil and reserved pasta cooking water. Puree until smooth. Be very careful when blending hot liquids. Make sure the lid is on tight and hold on.
Pour scallion puree over pasta and add remaining sautéed scallion/garlic mixture and Parmigianno-Reggiano. Toss together and serve immediately.