To the starter, add salt, melted butter, 2 tbsp sugar, and warm milk. Whisk in 3 cups flour and mix well. Then move to a wooden or sturdy-handled spoon and add another 2 cups flour mixing well. Continue to add ½ cup of flour at a time until the dough is a shaggy mess (5 ½ - 6 cups total). You many need to knead in the last ½ - 1 cup of flour.
On a lightly floured surface, scoop out the dough and knead until it is elastic (about 10 minutes).
Place the dough back into the bowl. Cover the bowl with plastic wrap sprayed with cooking spray and set the bowl in a warm area until the dough has doubled in size ~ hour.
Deflate the dough and scoop it back out onto a lightly floured surface. Knead a little more. Shape the dough into a simple rectangle. Using a sharp knife, cut the large loaf in half to make two loaves.
Move one half aside and flatten the other half with your hands into a rectangle. Use the French omelet/letter fold to shape the dough. Fold one third over to the center and pinch the seams together. Then, fold the other side over to the center and pinch the seams together. Voila! Fancy French fold.
Manipulate the dough a little to make it fit into a greased loaf pan. Use the edges of your palms and flatten the end enough to make a crease that will allow you to fold under the ends so you have a pretty and smooth dough on the top and sides. Place dough seam side down into a greased loaf pan.
Repeat steps 5 and 6 with the other dough half.
Cover both pans with plastic wrap sprayed with cooking spray. Set both in a warm space to rise ~an hour. The dough should rise above the pans.
Preheat oven to 375˚F / 191˚C. Place a cookie sheet on the bottom rack level with the top rack in the middle position.
Brush both dough tops with egg wash using the 1 beaten egg. Score the tops of each using a sharp knife. Make crisscross slices to form diamond-like shapes or any pattern you want. Sprinkle on flour to get that artisan look.
Boil 1 cup water to pour into the cookie sheet when you place the bread in the oven. The hot water will produce steam that will crisp up the bread edges.
Place the two loaf pans in the oven, quickly pour the hot water into the cookie sheet and shut the oven door. Bake for 35-40 minutes or until the internal temperature reaches 190˚F / 88˚C.
When baked, let the bread cool in the pans for 10 minutes. Then, remove, slice, and enjoy!