Mix together the three flours, yeast and salt. Add shortening and just enough water to make a dough that comes together (about 75 grams). Add the chopped walnuts, and knead the dough on a lightly floured surface for 7 to 8 minutes or until the dough is smooth
and elastic. Lightly oil a large bowl and place the dough into the bowl. Cover with plastic wrap and let rise until doubled in size, about 1 1/2 to 2 hours.
Preheat oven to 400 degrees F. Divide the dough into 12 equal sized balls. Line baking sheets with silicone sheets, or cornmeal. On a lightly floured surface, use a rolling pin to roll the balls of dough into flat ovals about 7 inches long and 5 inches wide. Start at one end and roll each oval into a fat tube and carefully place on the baking sheet. Continue with the remaining dough balls and place on the baking sheets leaving 2 inches between rolls. Cover with kitchen towels and let rise 45 minutes. Use a bread lame or sharp knife to cut slits on top of each roll. Bake for about 30 minutes or until the internal temperature of the rolls is 190 degrees F. and rolls are lightly browned. Cook on a wire rack and store in an airtight container.