Ben Siman Tov
Make a tea using the water, the hibiscus, 10 grams of rose petals, and 5 grams of sumac. Let it cool to room temperature. Strain the flowers out.
In a little bowl mix the remaining 10 grams of sumac and 20 ml of water.
In a stand mixer mix the the flower tea, sugar and yeast. Let it sit for 10 min.
Add the egg, then add the flour and then the olive oil. Switch to a dough hook.
Start kneading the dough until it starts to come together. Add the sumac and water.
Knead for 4 minutes and then add the salt.
Increase the speed of the mixer by one level and and knead for 8 minutes more.
Roll the dough into a ball and place in a greased bowl covered with a towel. Let it rest until doubled in size.
Divide as you like, I divided this beauty into 6 pieces of 150 grams each.
Roll each piece into a ball and then cover them with a towel for 10 minutes.
Roll the balls into strands and then braid your challah, decorating it with the remainign rose petals.
Let the bread proof, you will know it is ready to make when you gently press the dough and it rebounds slowly.
Brush with egg yolk mixed with a bit of water. Don't make a pool of egg on the challah. Light brushing. We don't want an omelette on our bread!
Bake in a preheated oven to 380F or 190C for about 25 min. If the top of the challah gets brown too fast, cover the top with aluminum foil.
Cool on a rack.