Gougères, or savory French cheese puffs, make great holiday party apps. They are a savory take on pâte à choux, cream puff dough. It's the same dough used in éclairs and in beignets, where it's deep-fried instead of baked. "Choux" means cabbage; the name comes from the fact that just-baked cream puffs look like little cabbages. 

One interesting thing about pâte à choux is that achieves leavening not from yeast or baking powder. Its rise (or "puff") comes from high moisture content, which creates steam voids during baking. 

The addition of grated cheese makes gougères a bit less puffy. Gruyère is a sure bet, but other dry cheeses (like Parmesan) work too.

If you're interested in a refined presentation, you can use a Pastry bag to form the puff neatly & uniformly. 

1 cup water
4 oz (8 tablespoons) cold butter, chopped into small pieces
1/2 teaspoon salt
1/4 teaspoon black pepper
1 cup AP flour, sifted
4 eggs
1 cup grated Gruyère, separated into 3/4 cup for the dough and 1/4 cup for sprinkling on uncooked puffs

Heat oven to 425F and line two cookie sheets with parchment

In a medium saucepan, combine water, butter, salt, and pepper. Stir slowly and bring to a boil over high heat. When the water is at a low boil and all the butter melted, remove from heat.

Immediately add the cup of flour and beat vigorously with a large spoon to blend thoroughly. Then return to medium heat and continue beating for a minute or two, until the mixture has dried a bit and pulls away from the side of the pan.

Remove from heat. Beat in the eggs one at a time until well combined. Add the 3/4 cup of Gruyère in two batches with the 3rd and 4th eggs. When done, the ingredients should be smoothly combined.

Form into 1-1/2 to 2-inch rounds, 2 inches apart on cookie sheets (you'll need at least two, to accommodate 40 or so puffs). When all the puffs are formed, sprinkle the 1/4 cup of Gruyère on them, a pinch at a time.

Bake at 425F for about 20-25 minutes, until golden brown.