To Make Sweet Dough: In a medium bowl combine the yeast, sugar and water and mix together; let stand 10 minutes. Stir in flour, dry milk, baking powder and shortening, then knead mixture for 10 minutes, adding as little flour as necessary. Cover bowl with a damp cloth and let rise in a warm place for 30 minutes, then knead again.
To Make Filling: Meanwhile, brown beef, sausage and onion in a large skillet over medium high heat. Drain extra fat from skillet, then stir in cabbage, mustard, salt and pepper and cook for 5 minutes. Add cheese and cook, stirring, until cheese is melted.
Preheat oven to 350 degrees F (175 degrees C).
Flatten a piece of dough. Place large spoonful of meat filling onto dough and fold over to form a round bun. Lay folded-side-down in a lightly greased 9x13 inch baking dish. Repeat with remaining dough and filling.
Bake in preheated oven for 20 minutes, or until golden brown.
