1 cup flour
1 cup water
1 1/2 teaspoons salt
1/2 stick butter (4 tablespoons), cut into small slices for easy melting
1 cup shredded cheddar cheese
1 egg yolk
1 1/2 tablespoons black pepper
1 1/2 tablespoons ground mustard
Pre-heat your oven to 425°F.
Prepare your ingredients first: In a deep-dish/skillet frying pan, place the one cup of water, salt and butter. Have your 1 cup of flour ready on the side. In a 2-cup cup, place your shredded cheddar cheese, powdered mustard, pepper, garlic and basil. Put your eggs and egg yolk in a bowl and beat them well. Once you have these things ready, get out a mixing bowl, you will need this soon.
Turn on the deep-dish/skillet pan with the water/salt/butter, and when it comes to a rolling boil, add the entire contents of the flour into it in one dumping and stir vigorously. The mixture, within about 10 seconds, will solidify into something that looks like chocolate chip cookie dough, and will no longer stick to the sides of the pan. Remove from the stove and put this dough into the mixing bowl.
Add in the eggs and stir. The mixture will act like it doesn't want to mix with the eggs, but continue to stir (you can also use a mixer if you like) until it's completely mixed together. Add the cheese, mustard, pepper, garlic, and basil into the mix, and mix it well.
Grease a cookie sheet. Spoon the mixture into little drops on the cookie sheet (I usually manage to fit 48 drops on the sheet: 8 rows of 6). The puffs will not spread out like cookies do, they will remain the same size as you put on the sheet.
Bake for 20 minutes on 425°F. After that, lower the oven to 350°F, and bake an additional 15 minutes.
Remove from the oven, and immediately loosen them up with a spatula, to prevent from sticking to the sheet. Cool a little, but they're best when served warm and fresh, still crispy on the outside.