Preheat oven to 400 F. Mix the dry ingredients (cornmeal, wheat flour, baking powder, sugar, salt and pepper) in a bowl. In another bowl, mix egg, milk, oil and butter and then slowly add the liquid to the dry ingredients. Stir until mixed. Add the chopped vegetables to the batter and mix well. Grease muffin tins and fill each cup ~3/4 full. Bake for ~25 minutes until golden brown.