Cacio e pepe is practically synonymous with Pecorino Romano -- but Pecorino clumps when cooked. Add it at the end, instead, which also makes the most of its sharp flavor. Lemon adds spunk -- that is, acidity and freshness.
There are cards to write, presents to wrap, and friends stopping by. When you're swept up in the holiday whirl, getting a weeknight meal on the table can be a challenge. The solution: Cook the components of this hearty shepherd's pie up to five days in advance, and then assemble and bake -- in batches big and small -- whenever the joyous chaos allows.