Allow the puff pastry to thaw to room temperature.
Heat the oil and sauté the onion until browned. Add the ginger and continue to sauté for a couple of minutes. Mix the curry powder and turmeric with enough water to make a wet paste, and add it to the onion mixture. Sauté for an additional 3 to 4 minutes. Add the chiles, tomato, chicken, and potatoes, season with salt and cook for 5 minutes. Set aside to cool.
To assemble, roll out the pastry to about 1/8″ and cut into 3 ½-inch circles. Brush the edges with milk, add a tablespoon of the curry filling, fold the edges closed and crimp decoratively with a fork. Brush the pastries with the egg wash.
Bake on an ungreased cookie sheet for 12 to 15 minutes or until the curry puffs are golden brown and puffed. Serve warm.
