Smoked Salmon and Chive Puff Pastry Mille Feuille

Name: Smoked Salmon and Chive Puff Pastry Mille Feuille
Ingredients: 2 cups unbleached all-purpose flour , about 9 ounces (255 grams); 20 tablespoons unsalted butter , cold, cut into 1/2-inch dice (4 tablespoons kept separate); 1 teaspoon table salt; 6 tablespoons cold water , plus a tablespoon more, if necessary; 8 tablespoons unsalted butter , softened; 8 ounces (227 grams) cream cheese , softened; 1 medium lemon , zested to yield 1 tablespoon zest; 3 tablespoons minced fresh chives , or snipped; 6 ounces (170 grams) smoked salmon , sliced thin