Dough: In a stand mixer with the dough hook, combine the flour, sugar, yeast, and salt. Add the egg, warm milk, cooled tangzhong, and softened butter. Mix on low until it comes together, then increase to medium and knead 8 to 10 minutes until smooth and elastic. The dough should be soft and tacky, but workable. If it's still super super sticky and making a mess after 10 minutes, add flour a tablespoon at a time. In the last minute, add the garlic, diced jalapeño, and chives and let the mixer work them in.