Steamed Berry Varenyky

In a large bowl, mix all the dough ingredients (kefir or buttermilk, egg, all-purpose flour, 2 tsp sugar, instant yeast, baking soda, neutral oil, salt) until a soft dough forms. Cover the bowl and let the dough proof for about 1 hour. Roll out the dough to approximately ¼-inch thickness and use a cutter to cut it into 3-inch circles. In a small separate bowl, combine the filling sugar (½ cup) and cornstarch. Place 2–3 berries (raspberries and blackberries) in the center of each dough circle, then sprinkle with ½ teaspoon of the sugar and cornstarch mixture. Fold each circle into a half-moon shape and pinch the edges tightly to seal. Steam the varenyky for 8 to 10 minutes, or until the dough is cooked through. Serve warm, drizzled with honey and accompanied by a spoonful of sour cream.