Preheat oven to 170 degrees F. Fill a glass measuring cup with 1 cup of water. Place in microwave and heat for 3 minutes, or until water is boiling.
In another glass measuring cup, fill it with 1/3 cup warm water. Sprinkle the 1 Tablespoon of yeast over the water. With a fork, stir yeast into the water until yeast is completely dissolved.
Pour the sugar, salt and shortening into the bowl of your stand mixer. Using a fork, mash these ingredients together. Pour the 1 cup of boiling water over the shortening mixture in the stand mixer. Add the 1 cup of cold water into the mixer. Then pour in the yeast/water mixture.
Add 3 cups of flour into the mixer, and using the dough hook, turn mixer on low speed. With the mixer still on, slowly add in the remaining 3 cups of flour, 1 cup at a time. Once all 6 cups are in, turn speed to medium and let the dough mix for 6-8 minutes. The dough should be nice and elastic. Be careful not to over-flour. I used all 6 cups, but would not use any more than that.
Once the dough is mixed, let it rest in the bowl for 5 minutes.
Spray a large cookie sheet with non-stick spray. After the dough has rested in the bowl, dump it onto the greased cookie sheet.
Take a sharp knife, spray it with non-stick spray, and cut dough into 3 equal pieces. Then let it rest again for 5 minutes. (These resting periods for the dough is needed, so please do it and be patient! It’s worth the wait )
To shape the dough before baking: Take one section of dough and spread it out into a rectangle. Just use your fingers, you don’t need a rolling pin. Fold one long end up over half of dough, then fold the other half over that one. Then fold each side up over each other, then turn the loaf over so it is seam side down.
Use your fingers to tuck seams down underneath the loaf and shape it. Repeat with the other 2 pieces of dough. Once all 3 sections of dough are shaped cut 3 angled 1/2 inch slits onto the tops of dough.
Crack the egg into a bowl and whisk with a fork until frothy. Spread the egg over the tops of each loaf, making sure to get inside the slits.
Place the loaves into the oven and let them rise for about 15 minutes (while the oven is on 170 degrees F.) Then turn oven up to 400 degrees F (while the loaves are still inside) and bake for 15-20 minutes, or until the tops are golden brown and crisp. Turn the oven down to 350 degrees F. and bake for an additional 10 minutes.
Remove the loaves from the baking sheet and allow them to cool a bit before slicing them.