Saute onions in olive oil until soft, but not brown. Set aside and cool. In a large bowl, stir yeast into water to soften. Add milk, shortening, honey, salt, 2 cups flour and cooled onions. Beat vigorously for two minutes. Whisk sage and whole wheat flour together and add to onion mixture. Stir to incorporate. Gradually add flour, 1/4 cup at a time, until the dough begins to pull away from the side of the bowl. Turn dough out onto a floured work surface. Knead, adding flour a little at a time, until you have a smooth, elastic dough. Put dough into an oiled bowl. Turn to coat the entire ball of dough with oil. Cover with a tightly woven towel and let rise until doubled, about one hour. Turn the dough out onto a lightly oiled work surface and divide into 36 equal pieces, Shape each piece into an 8-inch strand and tie it into a single knot. Place about three inches apart on parchment-lined baking sheets. (These knotted rolls are also attractive if placed into well-greased muffin pans.) Cover with a tightly woven towel and let rise until almost doubled, about 45 minutes. About 10 minutes before baking, preheat oven to 400 degrees. Bake for 15 minutes, or until the internal temperature of the rolls reaches 190 degrees. Immediately remove rolls from baking sheets and cool on a rack. For a shiny, soft crust, brush the tops of the rolls with olive oil.