Dissolve the yeast in the water and let it sit for 10 minutes

Add to the yeast mixture the salt, sugar, kefir, butter, and 200 g of flour and combine everything until you get a paste.

Add the paste to the leftover flour and incorporate all the ingredients until there are no dry flour particles. Let it sit, covered, for 20 minutes

Knead the dough until it's elastic and soft

Place the dough on a lightly oiled bowl and let it ferment, covered, until it doubles in size and it's puffy.

Deflate the dough and knead it for 1 or 2 minutes to make sure you get rid of big bubbles

Divide the dough in 4 equal pieces. Shape them into balls, cover them and let them rest for 10 minutes.

With a rolling pin roll the balls into a rectangle and shape the loaves.

Let the loaves rest, covered, until they double in size and they are puffy.

Make cuts on the loaves, brush them with water (optional) and bake them at 375 F for 25 minutes or until they're golden brown