You can’t eat just one. Try it.
1/4 cup butter
1 cup plus 1 tsp water
1/2 tsp salt
1/4 tsp dry mustard
1/2 cup flour
2 eggs (plus 1 later on)
1/4 lb finely diced gruyere cheese
2 tsps grated parmesan cheese
2 oz finely diced pancetta – sauteed crisp and cooled
Place butter, water, salt and mustard powder in a pot and bring to a boil. When butter is melted, remove from the heat and add the flour all at once. Stir with a wooden spoon until a smooth dough forms. Return pan to heat and beat dough until it forms a mass and pulls away from the side of the pan – about 1 minutes.
Remove pan, and put the mixture into a mixer bowl. Mix on mixer for a couple of minutes to slightly cool the mixture. Add the 2 eggs, one at a time, until well combined and the dough is smooth and shiny. Add the gruyere and pancetta.
Drop dough (approx 1 tbsp each) onto a greased or silpat lined baking sheet. Beat the extra egg with 1 tbsp water till smooth. Brush the egg mixture onto the puffs. This is a good time to “shape” the mounds with the brush. Sprinkle with parmesan.
Bake at 400 degrees for about 15-20 minutes or until puffed and brown.