Combine the kefir and butter in a food processor or blender. In a separate bowl mix together the flour and salt. Pour the kefir mixture into the bowl with the flour and work the dough into a ball. Cover and let it sit for about 24 hours.
When you are ready to fill and bake the samosas take a scoop of dough, about the size of a large cookie, place it on a floured surface and roll it out with a rolling pin. You want it fairly thin but not so thin it won't hold together.
You can make small or large samosas by altering the amount of dough for each pastry. I like to make them long and thin, like a small hot dog because they're easier to hold. Just place your filling onto the dough and fold the dough up over the filling.
Place the samosas on a greased cookie sheet and bake at 350 for about 30-45 minutes or until the dough feels done to the touch. The filling is already cooked, no need to overbake. Serve with Fermented Peach Chutney and creme fresh, sour cream, or fresh yogurt. Sprinkle with fresh chopped cilantro.