Prepare and chill Quick-Method Croissant Dough as directed. Cut dough crosswise into 4 portions. Wrap and return 3 portions to refrigerator until ready to use.
To shape croissants, on a lightly floured surface, roll 1 portion of dough into a 16x8-inch rectangle. Cut rectangle crosswise in half to form 2 squares. Cut each square diagonally in half to form 2 triangles. (You will have 4 triangles from each rectangle.) Loosely roll up each triangle from an 8-inch side, rolling toward opposite point.
Repeat cutting and shaping with remaining 3 portions. Place croissants, points down, 4 inches apart on ungreased baking sheets. Curve ends. Cover and let rise in a warm place until double (about 1 hour).
Beat egg and the water or milk using a fork. Lightly brush croissants with egg mixture. Bake in a 375 degree F oven for 15 minutes or until golden. Remove from baking sheets. Cool slightly on wire racks. Serve warm or cool. Makes 16 croissants.