Mix seasoning ingredients and store in an airtight container. In a small skillet, cook onion and seasoning in 1 tablespoon butter until onion is tender. In mixing bowl, stir together the flour, baking powder and salt. Cut in the shortening until mixture resemble coarse crumbs. Combine onion mixture, egg and milk; add to flour mixture all at once. Stir until dough clings together. Knead on lightly flour surface 10 to 12 strokes. Roll or pat dough to 1/2 inch thickness. Cut with a floured biscuit cutter. Place close together in a greased 8x1 1/2 inch round baking pan. Melt remaining butter and brush over dough. Sprinkle with cheese. Bake at 450~ for 12 to 15 minutes.