Warm the milk and dissolve the yeast in it, add about 500 gr of flour to make a batter and let it stand for  2 1/2-3 hours so that it rises well (you can also do that from the previous evening, you save a lot of time and they are more traditional this way). 

Put the rest of the flour in a large bowl and make a well in the middle. Add the eggs beaten with the sugar, 1 shot of the water with the mahlab, the mastic, the zest and the leaven and knead starting from the edges to the center. 

Add the warm butter last and knead till it is incorporated with the rest of the ingredients. 

Let the dough rise for  2 1/2-3 and then knead thoroughly once more. 

Let it rise once more, press it lightly to deflate and form the tsourekia in the shape that you desire. Place them on a buttered tray and let them rise well. 

Preheat the oven at 180 degrees, brush the tsourekia with the egg yolks and sprinkle with the almonds.

Bake for 30`-40, depending on their size.