In a large mixing bowl, combine 3 ½ cups of all-purpose flour, 1 tablespoon of sugar, and 1 teaspoon of salt. Sprinkle in 2 teaspoons of active dry yeast. Gradually add 1 cup of warm water, mixing with a wooden spoon until a sticky dough forms.

Transfer the dough to a floured surface and knead for about 10 minutes until smooth and elastic.

Lightly grease a large bowl with vegetable oil, place the dough inside, cover with a damp cloth, and let it rise for approximately 1 hour until it doubles in size.

Once risen, punch the dough down, divide into 12 equal portions, and roll each into a smooth ball. Flatten each ball into a 4-inch circle.

In a skillet over medium heat, cook your choice of protein seasoned with soy sauce and Sriracha for 8-10 minutes, or until caramelized. Stir in chopped vegetables.

Place a spoonful of filling into the center of each dough circle. Fold edges together and pinch to seal.

Arrange bao buns in a bamboo steamer lined with parchment paper and steam over boiling water for 15 minutes.

Carefully remove the steamed bao buns and serve warm with your favorite dipping sauces.