Preheat the oven to 400º, and line heavy baking sheets with parchment paper.

In a 3-quart heavy saucepan, heat milk, water, butter, and salt, until butter is melted.

Keep pan over low heat, and add flour all at once, stirring constantly.

Continue to stir until the mixture is uniform, and has pulled away from the sides of the pan, forming a ball around the spoon.

Remove the pan from the heat, and let it rest for about 5 minutes, to cool the mixture slightly.

Add the eggs, one at a time, completely incorporating each one, before adding the next. Work quickly, especially the first one, so the eggs don't cook at all in the warm flour mixture. At the start of adding each egg, it is going to feel as though it will never come together, but just keep mixing, and it will. This can be done with a mixer if you prefer.  I like a wooden spoon better though.

Once all 4 eggs have been completely mixed in, add 4 ounces of the cheese and the herbs, mixing until uniformly blended.

For the cheese, you can use any kind that is fairly dry. Gruyere is traditional, but I used a mixture of extra sharp cheddar, asiago, and romano.

You can use a pastry bag to pipe these onto the baking sheets, but I find my smallest cookie scoop works as well. If you have any sort of peak on them once they are on the pan, wet your finger, and gently pat it down – otherwise, you will have little burned points on the finished puffs.

Top each puff with a little sprinkle of the remaining cheese, and place sheet pans in the preheated oven for 5 minutes. Lower heat to 375, and continue to bake for another 20 minutes.

Pierce the side of each puff with a skewer or the tip of a sharp knife, and return to the oven for a final 5 minutes, until the tops are a deep, golden brown. [if you forget the piercing part, it is not the end of the world, so don’t overbake them just to get that part in] Cool briefly and serve warm.

You can prepare them ahead, right up to the baking and let them sit for a few hours, until you need them. Or, you can portion them out on parchment-lined sheets, and then stick them in the freezer for a few hours, and then place them in a freezer container of some sort for up to a month. Bake them right from the frozen state as outlined above, and they will taste just as good as the ones you bake right away. This is especially handy if you are preparing some things ahead for a party, because it makes it so easy to get them ready when you need them.