Grease a 9-inch by 5-inch loaf pan or line it with parchment paper, and heat the oven to 350 F.
Remove the bananas from their peels, and return them to the colander. Set the colander in the sink or over a bowl to allow excess liquid to drain.
While the bananas drain, sift the einkorn flour with the baking soda and salt into a medium bowl, and set it aside.
Place the butter and jaggery into a stand mixer, and cream them together at medium speed until lightened and fluffy. Add the eggs and bananas, and beat them together until uniformly combined.
Beat one half of the flour into the liquid ingredients, and then pour in the kefir, and then beat in the remaining flour.
Fold the nuts and chocolate chips into the batter, and then pour the batter into your prepared loaf pan. Bake at 350 degrees for 70 minutes or until it springs back when lightly touched in the middle. Remove from pan and cool on a wire rack.
Substitutions. If you can't find jaggery, you can substitute organic dark brown sugar. If you don't have kefir, you can substitute ⅓ cup milk plus 1 teaspoon apple cider vinegar.