These delightful pastries are made with a unique dough that rises beautifully thanks to the use of kvass, a traditional fermented beverage. The filling features a rich liver mixture that is seasoned to perfection, delivering a burst of flavor in every bite. This recipe is perfect for family gatherings, parties, or simply as a flavorful snack. The dough is soft and fluffy, while the filling is hearty and satisfying, making these pastries a beloved treat. Enjoy them warm from the oven for the best experience, and serve with a side of sour cream or your favorite dipping sauce.