This is the delicious marriage of orzo pasta and fettuccine Alfredo. We cook the orzo like rice, as if making risotto, so the starches create a creamy, silky sauce. Butter and Parmesan join the mix as a nod to Alfredo, and sweet peas add color and sweetness. For the lushest texture, use a good-quality bronze-cut pasta; it will release more starch during cooking. At the supermarket, look for orzo with a rough, floury appearance. Widely available De Cecco works well, as does DeLallo.