In the bowl of a stand mixer fitted with a dough blade or a large bowl, sprinkle yeast over lukewarm water. Allow to sit until frothy, about 10 minutes.
Mix in the flour, egg, sugar, and salt until a smooth dough comes together. If too sticky, add a little more flour. If too dry, add a little more water. Cover the dough and refrigerate for 3 hours.
On a lightly floured surface, roll the rested dough into a large square. Thinly slice the chilled butter and arrange in a layer at a 45˚ angle of the corners to make a diamond inside the square. Fold in the corners of the dough towards the center and seal to enclose the butter layer.
Being careful to not crack the dough and expose the butter, roll the dough into a rectangle about 7x23 inches. Fold 1/3rd of the dough inward towards the center followed by the other side to create three layers. Cover in plastic and refrigerate for 30 minutes. Roll the dough out again and fold inwards again, then refrigerate another 30 minutes. Repeat the process one more time for a total of three times.