In a bowl, combine all-purpose flour, salt, and ground white pepper. Create a well in the center.

Gradually add whole milk, then water, whisking continuously until the batter is smooth.

Beat in eggs until well combined.

Let the batter stand for 30 minutes.

Preheat a standard size muffin pan in a 425 degrees F oven for 5 minutes, or until very hot.

Remove the hot muffin pan from the oven.

Carefully spoon 1/2 teaspoon of oil into each of the 72 cups (or into each of 18 cups for a trial recipe).

Spoon 2 tablespoons of batter into each cup.

Bake for 15 minutes, or until the puffs are puffed and well browned, rotating the pan halfway through the baking time.

Carefully remove the puffs from the pan and let them cool.

For each serving, place 1/2 oz of roasted beef on each of 3 puffs.

Drizzle each puff with 1/2 teaspoon of bistro sauce.

Garnish with a pinch of finely chopped fresh chives.