Birria Bao

In a stand mixer with the dough hook attached, add the flour, yeast, sugar, baking powder, then oil. With the mixer on low speed, gradually mix in the milk; then the water and salt, mixing just until incorporated. Increase the speed to medium and knead until the dough is very soft and elastic, but does not stick to your fingers or the mixing bowl, 4 to 5 minutes.

Lightly grease a medium bowl. On a work surface, form the dough into a smooth round ball. Transfer the dough to the bowl. Cover with a damp cloth or plastic wrap and let rest in a warm, draft-free place for 30 minutes.

Line a bamboo steamer with a parchment-paper round. Set another parchment-paper round nearby. On a lightly-floured surface, roll out the dough to about 1/4-inch thick. Using a 3 1/2-inch round biscuit cutter, cut out 10 rounds. Fold the rounds over, forming half moons (do not press together). Place 5 bao in the steamer, spacing apart, and cover with the lid. Place the remaining 5 bao on the other parchment-paper round and cover with an inverted bowl. Let the bao rest for 30 minutes.

Bring 2 inches of water to a simmer in a wok or a large skillet. Place the bamboo steamer on top and steam the bao until the bread is cooked, about 12 minutes. Repeat with the remaining bao, adding more water to the wok if needed. When the bao are cool enough to handle, fill with the warm birria and garnish with onion, chiles, avocado, and cilantro. Serve with lime wedges.