Fry the bacon and onion in a 25 cm skillet, over medium heat, for 5 minutes or until the bacon is crisp and the onions are tender. Remove the bacon and onion and drain on paper towels. Sift the flour, corn meal, sugar, baking powder and salt into a bowl, and set aside. In another bowl, combine the eggs, milk, and butter, blending well. Add the egg mixture, all at once, to the flour mixture, stirring just until moistened. Stir in the bacon-onion mixture, and cheese, blending well. Spoon the batter into greased 8 cm muffin-pan cups, filling each two third rds full. Bake in a preheated 200ºC . oven for 15 minutes or until a wooden pick inserted in the center of a muffin comes out clean. Cool, until cold to the touch, and wrap in foil, or serve immediately while still hot. TO REHEAT: Heat the foil-wrapped muffins in a preheated 180ºC . oven for 10 to dozen minutes.