In a small bowl, combine the flour, baking soda, and salt.
Using an electric mixer beat together the honey, egg and oil in a large bowl until it is smooth. Add half of the flour mixture and continue to mix on medium speed. Beat in the buttermilk, and then add the remaining flour mixture. Blend well, and then add the mashed banana. Add the currants OR raisins and the walnuts, and then stir well until combined.
Pour the batter into a cooking spray coated 9x5 pan and bake for about 50 minutes, or until a toothpick inserted into the loaf comes out clean.
Turn the pan out onto a rack to cool completely before slicing and serving.