An Armenian savory cookie that goes by many names: Khalkha / Simit / Kekhke. If you ask Armenians (I did) what they call it, you'll get a lot of different answers, but we are unified in loving these cookies! There are sweet versions too, but this is the savory one my family prefers.
Mix the warm water and yeast in a small bowl and allow the yeast to bloom for about 10 minutes until softened and dissolved.
In a large mixing bowl, combine the nigella seeds and kosher salt. Stir in the water/yeast, melted butter, and oil. Slowly add the flour, stirring with a wooden spoon until it becomes thick enough to mix with your hands. Continue to mix/knead the dough until it becomes smooth, soft, and pliable.
Cover with a kitchen towel and allow to proof in a slightly warm space for 1 ½ hours, or until about double in size.
Preheat the oven to 375°F placing the racks in the upper and lower thirds of the oven. Line several baking sheets with parchment paper and set aside.
Cut portions of the dough with a knife, covering the remaining dough until needed. Roll each portion into a rope about ¼-inch thick on an unfloured work surface (alternatively, pinch off smaller pieces of dough and roll them out individually). To create twists, cut into segments about 4-to-6-inches in length. Fold each segment to bring the ends together, pressing gently, and then twist (the length will determine the size of the twists). To create rings, cut the segments into 4-inch pieces and pinch together the opposite ends to yield a circle. Place each twist or ring on the parchment-lined baking sheets, setting them about 1-inch apart.
Brush the beaten egg over each khalkha and then place baking sheets in the oven (you may need to bake them in batches) for about 30 to 35 minutes, rotating the pans from front to back and top to bottom halfway through. The khalkhas are done when they are golden and crisp. Remove from the oven and allow to cool completely before serving.
Khalkha can keep in an airtight container for about a week and can be frozen.
This recipe uses kosher salt (aka cooking salt, kitchen salt, coarse salt outside of the US). If you are using table salt, definitely scale down the salt as that is a saltier type of salt! The type of salt will make a big difference in how salty your food tastes, so keep that in mind.