Preheat oven to 300°. To start dissolve yeast in warm water. Combine dissolved yeast, chicken stock and egg. Mix well and set aside. Combine all dry ingredients. Slowly add liquids to dry mix stirring as you go. Knead dough for about 3 minutes until stiff. Roll 1/4 " thickness and cut with cookie cutter. Place oiled cookie sheet and bake for 45 minutes. Turn oven off and let biscuits sit in oven until bone hard.