Mix the ingredients. Combine all ingredients except the salt and butter in a large mixing bowl. Mix until a shaggy dough forms. Then, cover with a damp tea towel and rest at room temperature for 20-40 minutes.
Knead the dough. After the rest period, add the salt and knead the dough by hand, using a stand mixer or bread machine (dough cycle), for at least 5 minutes until the dough is soft, smooth, and elastic. Then, add the butter during the last minute of kneading.
First rise. Shape the dough into a ball and place it in a lightly oiled bowl. Then, cover it with a damp tea towel and place it in a warm spot. Allow it to rise for 3-4 hours until the dough is puffy.
Shape the loaf. After the dough has risen, shape it into a loaf by gently folding it and placing it into a greased 8x4-inch loaf pan. The dough may be slack but will take shape during the rise.
Second rise. Cover the pan with greased plastic wrap and allow the dough to rise for another 3-4 hours in a warm place until it rises about 1 inch over the edge of the pan.
Preheat the oven. Preheat your oven to 350°F (177°C) toward the second rise’s end.
Brush with egg wash. Before baking, brush the top of the loaf with the beaten egg for a glossy finish.
Bake the bread. Bake the loaf for 45 minutes until golden brown and the internal temperature reaches 200°F (93°C).
Cool and slice. Let the bread cool completely on a wire rack before slicing.