In a large mixing bowl, combine 3 cups of all-purpose flour, 1 tablespoon of sugar, and 1 teaspoon of active dry yeast. Gradually add 1 cup of warm milk while stirring to create a soft dough. Let it sit for 5 minutes.

Lightly flour your work surface and knead the dough for about 10 minutes until smooth and elastic. Form it into a ball.

Place the kneaded dough in a lightly oiled bowl, cover with a towel, and let it rise in a warm area for about 1 hour.

Punch the dough down and divide it into 8 portions, rolling each into a circle approximately 4 inches in diameter.

In a skillet over medium heat, cook your choice of protein with 2 tablespoons of soy sauce and a dash of Sriracha for about 5-7 minutes. Add chopped vegetables and stir-fry for an additional 3 minutes.

Place a spoonful of filling in the center of each dough circle, fold over, and pinch edges to seal tightly. Prepare a bamboo steamer lined with parchment paper and steam on high heat for about 15 minutes.

Remove the steamed buns and let them cool for a minute. Serve warm with dipping sauces.