Directions

For the Spice Blend

1. Mix together the nigella seeds and turmeric.

For the Challah

1. Whisk the warm water, yeast, and 1 teaspoon of the sugar (5 grams) in a medium bowl. Let stand until foamy, about 10 minutes.

2. Combine the flour, oil, labne, salt, 1 of the eggs, the spice blend, yeast mixture, and the remaining sugar (45 grams) in the bowl of a stand mixer fitted with the dough hook. Mix on low speed, scraping the bowl occasionally, until the dough comes together in a firm, stretchy mass, about 7 minutes.

3. Turn out onto a clean work surface and knead to form a tight ball, about 2 minutes. Lightly oil the mixer bowl, return the dough to it, and cover with a clean kitchen towel. Let rise in a warm spot until doubled in size, about 1 hour.

4. Line a half sheet pan with parchment paper. Turn the dough out onto a clean unfloured work surface and divide it into six equal pieces (about 108 grams each). Roll each into a 12-inch-long rope, pressing and roll- ing the ends to taper them.

5. Place two ropes parallel to each other, spacing them 3 inches apart. Cross the ropes once, leaving an inch free at the ends. Lay a third rope over the point at which the others cross. Braid the three ropes, tucking in the ends. Repeat with the remaining three ropes to form a second loaf. Transfer both braids to the prepared pan, spaced at least 5 inches apart. Cover with a clean kitchen towel and let rise in a warm place until puffed and the volume increases by about a third, about 45 minutes.

6. Position a rack in the center of the oven and preheat the oven to 400°F. Beat the remaining egg with a few drops of water and gently brush it over the loaves to lightly coat. Sprinkle with the sesame seeds. 

7. Bake until browned and well risen, 19 to 20 minutes. Cool completely on a wire rack.