Peel the onions and garlic, rinse with cold running water. Wash the greens and dry on a napkin. Sift the flour, this will help make it fluffier, the dough will be more tender, and it will be easy to knead. Remove the kefir from the refrigerator to allow it to warm to room temperature.
In a bowl, combine kefir, salt and sifted flour. Knead the dough. It should be soft and pliable and should not stick to your hands. Roll the dough into a ball, cover with cling film and leave at room temperature for 20 minutes. The dough will rest and become more elastic.
Chop the onion finely, into cubes, or grate it on a coarse grater. Finely chop the parsley with a sharp knife. Place the minced meat in a bowl and knead well; this will make it fluffier and more tender after baking. Add prepared onions and herbs to the minced meat, salt and pepper to taste.
Divide the prepared dough into two parts, alternately roll each into a layer 0.5 cm thick. Using a sharp knife, cut the layer into 5 cm squares. Place a teaspoon of minced meat in the middle of each. Press the edges of the dough together, leaving the middle open.
Grease a baking dish with vegetable oil and carefully place the open manti there. Place a piece of butter in the middle of each. Place the pan in an oven preheated to 180°C and bake for 10 minutes. Remove the mold and pour boiling water into it. The water should reach the middle of the manti. Return the pan to the oven and bake the manti for another 30 minutes, until the liquid has completely evaporated.
For the sauce, combine 100 ml of kefir and sour cream. Grate the garlic on a fine grater. Add garlic and herbs to kefir with sour cream. Add salt and mix thoroughly. Let the sauce sit for 10 minutes.
Serve manti as a separate hot dish. Place them in a common dish or serve in portions. Place manti around a bowl with sour cream and garlic sauce. Garnish as you wish: fresh dill, cilantro.