In a large mixing bowl, combine 500g flour, 3g yeast, and 5g sugar. Slowly pour in 270g warm water while stirring with chopsticks or a spoon until the mixture forms a shaggy dough.

Add 15g corn oil and knead the dough until smooth and elastic, achieving the "three shines" (smooth dough, clean hands, clean bowl).

Cover the dough with a damp cloth or plastic wrap and let it rest in a warm place for 45-60 minutes, or until it doubles in size.

Bring a pot of water to a boil. Add 1 tsp salt and 1 tbsp vegetable oil to the boiling water. Blanch the bok choy for about 1 minute until it softens and turns bright green.

Remove the bok choy and immediately plunge it into cold water to stop the cooking process and preserve the color. Squeeze out any excess water, chop finely, and set aside.

Soak the shiitake mushrooms in warm water if dried. Once rehydrated, remove the stems and finely dice the mushrooms.

In a pan, heat a small amount of oil over medium heat. Add the diced mushrooms and sauté for 2-3 minutes until fragrant.

Add the diced tofu to the pan and stir-fry with the mushrooms for an additional minute. Turn off the

Add in thechopped bok choy. Season with 1 tsp salt, 1 tsp chicken powder (or soy sauce for a vegan option), and 1 tbsp sesame oil. Stir everything together until well combined.

Once the dough has doubled in size, transfer it to a clean surface and knead for a few minutes to remove any air bubbles.

Divide the dough into 20 equal portions. Roll each portion into a small ball, then flatten each ball into a round wrapper, making the center slightly thicker than the edges.

Place about 1-2 tablespoons of filling in the center of each wrapper.

Gather the edges of the dough and pleat them together, pinching tightly to seal the bun. Make sure the buns are fully sealed to prevent the filling from leaking during steaming.

Place each bun on a small piece of parchment paper and arrange them on a steamer tray, leaving some space between each bun.

Cover the buns with alid or a damp cloth and let them rest for 15-20 minutes to rise again. The buns should feel slightly puffy to the touch.

Fill a steamer with water and bring it to a boil. Once the water is boiling, place the buns in the steamer, cover with the lid, and steam on high heat for 15 minutes.

After steaming, turn off the heat but leave the buns in the steamer for 3 minutes. This helps stabilize the buns and prevents them from collapsing when exposed to cooler air.

Carefully remove the buns and let them cool slightly before serving.