One of the easiest ways to show off is by making Duchess potatoes. It's a classic French dish which mixes finely mashed potatoes with egg yolks and a dash of nutmeg, squeezes the pureed mixture through a piping bag, and then browns them in the oven.
Just tweak the main ingredients. Instead of going with regular milk, use buttermilk, mayonnaise, sour cream or cream cheese. You can also brown your butter, or throw a little bit of truffle butter in there for extra flavor.
Changing the potatoes will make the least difference in terms of flavor, but red potatoes with the skins left on looks cool, and Yukon Gold potatoes make the dish a nice buttery yellow.
Don't go overboard – a Thanksgiving dish is a member of an ensemble, not a leading role. But it never hurts to add an extra savory element. The safest bets are garlic, crispy bacon, rosemary, scallions or cheddar cheese.
You don't have to show off the day of: offer to make breakfast on Black Friday and use your leftover potatoes to cook up Bubble and Squeak.
It's perfect for Thanksgiving because it allows you to incorporate pretty much all of your leftovers. It's like an omelette, but with potatoes as a base instead of the eggs.