Blend the cup of buttermilk and corn oil together. Add the cornmeal and steep it to soften for 15 minutes while you get all the other ingredients together.
Meanwhile sift the flour with the baking powder, baking soda and 1/2 teaspoon of salt.
Combine the bell pepper, with corn kernels, egg yolks and scallion and season with freshly ground black pepper.
Right before you begin to make the pancakes, combine the buttermilk and cornmeal mixture with the bell pepper, corn and scallion mixture and stir well.
Whip the egg whites until stiff but not dry. Preheat the griddle. With a few swift strokes fold the dry ingredients into the wet ingredients (add more buttermilk if needed) and fold in the egg whites. Drop about 1/4 cup of batter onto the griddle and cook for about 2 to 3 minutes per side.