Preheat the oven to 450 degrees F.
In a large bowl whisk together the flour, baking soda, baking powder and salt.
Cut the shortening and butter into small pieces and add to the dry mix. Using a pastry cutter, two butter knives or your fingers cut the shortening and butter into the mix until it resembles very small pebbles.
Add the diced sausage and rosemary and stir very briefly to coat with the flour.
Add the buttermilk and stir very briefly to moisten the ingredients.
Turn onto a floured surfae and knead 4 or 5 times. Roll out the dough until about 1 inch thick and cut using a floured biscuit cutter or wine glass. When all of the biscuits are cut, regather the dough and roll a second time. Place the cut biscuits on a parchment paper lined baking sheet and bake for 10 to 12 minutes or until golden brown on both top and bottom. Cool on a rack before serving.
