What makes the perfect Cacio e Pepe? Milk Street stops at nothing to find out! Christopher Kimball travels to Rome, where he learns that there are endless ways to make this seemingly simple dish with only three ingredients: spaghetti, pecorino, and black pepper. Then, Rose Hattabaugh unlocks the meaty side of zucchini with Zucchini Carbonara and Rosemary Gill offers a creamy, dairy-free version of pesto, Spaghetti with Parsley Pesto.