Dissolve yeast, sugar in warm water. Set aside. Sift all dry ingredients into a large bowl. Take the frozen butter and lard, and use a box grater to cut it into the flour. Make a hollow in flour. Mix yeast into buttermilk and pour into hollow. Stir. Add flour as needed. Turn dough out. Knead for 10 minutes. Add flour as necessary. Move to an oiled bowl, let rise, punch down and proceed to shape. Divide dough in half to shape. Roll till 1/3 to a ½ inch thick. Fold in half and roll until about 1 inch thick. Cut biscuits, do not twist cutter. Put on greased baking sheet. Let double/30 minutes. Preheat oven to 400. Bake for 6 minutes and rotate. Bake another 6 minutes till gfb. Remove, butter the tops. Once cool, you can freeze them. They keep quite well frozen.