Dissolve yeast in warm water. In a large bowl, combine hot water, sugar, salt, shortening, and 1/2 3 cups of the flour. Beat well with wooden spoon, or in a large mixer using a dough hook attachment. Stir in dissolved yeast. Add remaining 3 cups of flour, mixing well until blended.

Leave spoon/dough hook in batter, allowing dough to rest for 10 minutes. Stir again vigorously, allowing dough to rest another 10 minutes. Repeat until dough has been stirred 5 times.

On floured board, turn out dough and knead once or twice until it is lightly covered with flour. Divide dough in half. Roll each half into rectangles, about 9x12 inches. Starting at the long edge, roll loosely, like a jelly roll, sealing the edge.

Place roll, lengthwise, seam down on a large baking sheet, arranging so both loaves will fit on one sheet.

Gash top of each loaf diagonally with sharp knife, 3-4 times, then brush with beaten egg white and sprinkle with sesame seeds.

Allow loaves to rise 30 minutes. Bake at 400 degrees for 35 minutes, or until golden brown.