I come from one of those families where the Thanksgiving menu is essentially written on stone tablets. Many years ago, it was declared that there shall be turkey with stuffing (some cooked inside the bird and some cooked outside). Mashed potatoes are compulsory, as are sautéed Brussels sprouts, homemade gravy and cranberry jelly in the shape of a can.

When I was 12 years old, my cousin Jeremy brought an unscripted dish to our Thanksgiving table, but it was so wonderful that it was added to the holiday canon. It was a very large bowl of steamed and mashed butternut squash, enriched with a bit of powdered ginger and plenty of butter.

The only issue with this squash dish is that we somehow always manage to make so much of it that it ends up being totally out of proportion with the rest of the leftovers. The only thing that ends up outlasting is the gravy. (My father has trouble making less than a gallon of gravy.) Thankfully, I’ve discovered just the thing to transform all that squash and make it the most sought-after leftover around (though, if you make something else out of it, can it still be called a leftover?).

It’s a recipe for Baked Squash Gratin by Giada De Laurentiis and it’s just the thing for those Thanksgiving leftovers — and perfect for The Weekender.

Before you start layering pureed squash with pesto, here are a few things you should know:

• The recipe instructs you to steam your squash. However, if the oven is already going, you could also cut the squash in half and bake it to take advantage of the heat you’re already generating.
• When it comes to pureeing the cooked squash, a generous whirl in a food process or a blender works fine.
• Don’t be a hero. You’ve just spent days cooking a giant feast. Follow Giada’s suggestion and use store-bought pesto.

Marisa McClellan is a food writer and canning teacher who lives in Center City Philadelphia. Find more of her food (all cooked up in her 80-square-foot kitchen) at her blog, Food in Jars . Her first cookbook, also called Food in Jars , will be published by Running Press in spring 2012.