Cottage Pie

Yes. Prepare the beef filling and mashed potatoes separately up to 1 day ahead; refrigerate both in airtight containers. Assemble the pie on the day you want to eat it and bake as directed, adding 5–10 minutes if going straight from the refrigerator into the oven. Fully baked cottage pie keeps refrigerated for up to 2 days and reheats well covered at 350°F for about 25 minutes.

Cottage Pie uses ground beef; Shepherd's Pie uses ground lamb. Both are British classics and the recipes are identical except for the meat. Choose based on what you prefer—beef is milder and more widely available, while lamb is more traditional and more richly flavored.

For lumpiness, make sure to whisk the cornstarch slurry smoothly into the hot filling, a little at a time. For thin gravy, simmer the filling longer before adding the slurry, or double the cornstarch-water mixture. The gravy should coat the back of a spoon before you transfer it to the baking dish.

Yes. Assemble completely, cool to room temperature, wrap well in plastic wrap and foil, and freeze for up to 3 months. Bake from frozen at 350°F for 60–75 minutes, covered with foil for the first 45 minutes, then uncovered until the potato top is golden. You can also thaw overnight in the refrigerator and bake as directed.

A fresh green salad with vinaigrette or steamed peas and carrots provide welcome color and freshness. The pie is hearty and complete—no need for additional starches or heavy sides.

Cover and refrigerate for up to 3 days. Reheat covered with foil in a 350°F oven for 20–25 minutes until warmed through and the potato top is hot. Individual portions can be microwaved for 2–3 minutes, though oven reheating gives better texture.