Weight all of your ingredients and have them at room temperature.
Place into the mixer bowl the yeast combined with 1 teaspoon of honey, 1 tablespoon of flour and ¼ cup lukewarm milk. Mix it with a wooden spoon for 15 seconds and leave the mixture for 10 minutes to activate your yeast until it bubbles up.
Melt the butter in a saucepan over medium heat. When all the butter is melted, remove from heat and add the honey. Stir until honey is melted, add the milk, eggs, and vanilla extract, and stir them all together to bring the temperature down so that the yeast is not burnt.
Add the mahleb, the mastic and the cardamom into the flour and mix.
Pour the butter mixture into the mixer bowl and using the hook in low speed start to incorporate the flour in batches.
Knead the dough for 10 to 15 minutes, until it comes together but it is still slightly sticky.
Transfer the dough into a large bowl and cover with plastic wrap. Wrap it into a tablecloth and then in a blanket and let the dough rise for about 3 hours.
Unwrap the dough, butter your fingers and working space and separate the dough into 2 equally measured pieces.
Divide every piece into 3 equal pieces and roll them into strands (ropes).
Braid 3 strands into a bread, the dough is enough for 2 large tsourekia.
Repeat the same process with the second braid and place them on a lined baking sheet with parchment paper.
Cover them with a towel and let them rest, about 1-2 hours.
Preheat the oven at 180°C (350°F). Whisk the egg yolk with the milk.
Brush them lightly with the egg mixture and sprinkle them with sesame seeds or slivered almonds.
Bake the tsourekia for 25 minutes until golden brown. Remove from the oven and place them on a wired rack to cool.
Enjoy :)