In a large bowl, combine the cornmeal, flour, baking powder, sugar, salt and baking soda. In another bowl, whisk the egg, water, buttermilk and butter. Stir in the onion, jalapenos and green pepper. Stir into dry ingredients just until moistened.
In an electric skillet or deep-fat fryer, heat oil to 375°. Drop batter by teaspoonfuls, a few at a time, into hot oil. Fry until golden brown on both sides. Drain on paper towels. Serve warm.
Wear disposable gloves when cutting hot peppers; the oils can burn skin. Avoid touching your face.