Black Sesame Buttermilk Biscuits

Ingredients

• 18 ounces all-purpose flour, such as Gold Medal, plus more for dusting
• 1 ounce sugar
• 3/4 ounce roasted Japanese- or Korean-style black sesame seeds
• 2 tablespoons baking powder
• 1 teaspoon baking soda
• 1 tablespoon Diamond Crystal kosher salt; for table salt, use about half as much by volume or the same weight
• 6 ounces cold unsalted butter, cut into 1/2-inch cubes
• 13 1/2 ounces cultured low-fat buttermilk, straight from the fridge
• Sesame oil, for brushing

Directions

1. Set a rack in the lower-middle spot of the oven, then heat it to 400 degrees F, which is 200 degrees C. If your kitchen is hotter than 75 degrees F, or 24 degrees C, use the same warm-room habits you would for pie dough before you begin; they matter for biscuits too. Run the flour through a sifter into a medium bowl. Add the sugar and black sesame seeds, followed by the baking powder, baking soda, and salt. Whisk longer than seems necessary; a minute or more is fair game. Drop in the cold butter cubes, toss them around so they separate, then press each piece flat. Keep pinching and rubbing the butter into the dry ingredients until it nearly blends in, with a few larger pieces about the size of little cereal rings still allowed. You can also do this part in a food processor with 4 or 5 pulses, stopping before you take it too far. If you want to pause here, seal the mixture airtight and refrigerate it for up to 3 weeks, then continue with the recipe when ready.
2. Pour in the buttermilk and mix with a flexible spatula until no loose flour remains. It may look too dry and shaggy at the beginning, but stay with it until the dough gathers together. This is not the moment to be timid about mixing; while dry flour is still visible, undermixing is the bigger problem. When the dough has formed a rough ball, move it onto a lightly floured work surface.
3. With your hands, pat the dough gently into a rough square about 1/2 inch thick, then fold it in half. Repeat that pat-and-fold twice more so you have 3 folds total, adding only the flour you need to keep the dough from sticking to you. Pat the dough out again, this time to 3/4 inch thick. Brush off any extra flour if needed, cut the dough into 3-inch rounds, and nestle them close together in a 10-inch cast iron skillet. Pull the scraps into a ball, pat and fold them a single time, then cut out as many more biscuits as the dough allows. Press the last scraps together by hand into a single biscuit.
4. Brush the biscuit tops with sesame oil, then bake until they rise high and turn golden brown, about 30 minutes. Let them rest for about 5 minutes so the crumb can settle, then serve them fresh with soups and stews or as the bottom half of a fried chicken sandwich.