Dissolve yeast in lukewarm (or just slightly warmer than room temperature) milk and let stand until softened. Add beaten egg and refrigerate for about 15 minutes. Meanwhile sift 4 1/2 cups flour with 1 tsp salt and anywhere from 2 Tbsp to 4 Tbsp sugar and 1/2 cup butter. Make a well in the center of the flour mixture. Pour the chilled yeast-egg-milk mixture into it and mix well, grandually working the wet ingredients into the dry ingredients untila soft dough is formed. Then turn the dough out onto a floured surface and knead until it is smooth and shiny (about 2 minutes). Cover and refrigerate for about 20 minutes. Then (on a floured board or pastry cloth) roll the dough out into an oblong about 3/8" to 1/2" thick (the thickness of one finger). Dot one-fourth of your remaining butter (4 Tbsp or 1/4 cup) in tiny little dots over 2/3 of the surface of the dough. The butter must have about the same consistency as the dough. If it is too soft, it will melt into the dough, and you don't want that to happen. Fold the unbuttered third of the dough over the center third. Then fold the doubled or folded portion over the remaining butter-dotted third...like folding a letter to go in an envelope. Turn the dough (which is now in three layers) one quarter turn clockwise (sideways) and roll it out again just as before, about 3/8" to 1/2" thick. Repeat the butter-dotting and folding process just as before, three times more (four times in all), using 1/4 of the total 1 cup butter each time, and turning the dough one quarter turn clockwise each time after folding/before rolling out. If the butter begins to ooze during rolling, chill the dough before going on. When you have finished rolling, dotting, and folding (and turning!) the dough, cover and refrigerate it for about 2 hours. Cut the dough into three equal portions if you are going to be making all three different shapes of pastry (the three being envelopes, crescents and cockscombs). Roll out the dough (for the last time), shape and fill the pastries, cover them and let them rise for 20-25 minutes. Brush the finished pastries with beaten egg diluted with a little water or milk. Bake in a hot oven (375F-400F) until golden brown, about 15-20 minutes. Cool on racks. Pastries may be frosted with a confectioners' sugar glaze or icing if desired. Makes about 2 dozen.

that the butter doesn't warm up and start to melt. A marble slab is the ideal surface to work on, and cold fingers and a marble rolling pin are the best tools to work with. If you knead the butter with your hands in a bowl of cold water, you can soften it without raising its temperature, and it will by easier to work with.