From the 25 March 2009 New York Times, which took it from "Party Appetizers," by Tori Ritchie (Chronicle Books, 2004)
I made these with medium cheddar rather than sharp and they could have used some salt and pepper.
1 stick (8 tablespoons) unsalted butter, cut into pieces
1/2 teaspoon salt
1 cup all-purpose flour (i used freshly ground hard red wheat)
4 large eggs, at room temperature (who thinks that far ahead?!!)
1 1/2 teaspoons dry mustard
1/4 teaspoon cayenne pepper
1 1/2 cups (about 6 ounces) shredded sharp cheddar cheese
1. preheat oven to 375 derees. line two baking sheets with parchment paper or nonstick baking mats. in a medium-size heavy saucepan, combine 1 cup water, the butter and salt, and bring to a boil. turn off heat adn add flour. mix with a wooden spoon until dough starts to pull away from sides of pan and form a lump. set aside, without stirring, 5 minutes. (lumps of this stuff taste so yummy!!! esp. if you used good flour.)
2. add eggs 1 at a time, mixing well after each addition. with each addition, dough will look glossy and slick at first; let it come together before adding next egg. mix in mustard, cayenne and cheese. dough will be quite loose and sticky.
3. scoop up a heaping teaspoon of dough and use another spoon to scrape it onto lined pan; it should form a mound about an inch in diamter. alternatively, use a pastry bag or thick plastic bag with one corner cut off, to pipe small mounds onto pan. repeat with remaining dough, leaving 1/2 inhc between puffs.
4. bake until pffy and golden, about 25 minutes, rotating pans halfway through. remove from oven adn serve immediately, or turn oven off and open door slightly to keep puffs warm up to 1 hour.
yield: about 36 puffs