Mix flour, yeast, sugar and oil in a bowl. Pour in water little by little while mixing.
Combine and knead with your hands until a very smooth dough forms (see note 4).
Cover the bowl with a damp tea towel and leave to rise in a warm place until doubled in size (It will take between 40 minutes to 1.5 hours depending on the room temperature).
Mix the filling
Put pork, soy sauce, oyster sauce, salt and Sichuan pepper/Chinese five-spice in a mixing bowl.
Swirl constantly while gradually adding water/stock until no more liquid can be seen.
Brief stir fry grated carrot and onion in oil until softened. Add to the pork along with chopped coriander.
Shape the buns (Please refer to the video below)
Knead the dough until it goes back to its original size.
Divide it into 12 equal portions. Roll each piece into a disk-like wrapper.
Place some filling in the middle of a wrapper then fold into a bao shape.
Leave all the assembled buns to rest for another 15 minutes or so.
Steam the buns
Place the buns (with parchment paper underneath each one) in the steamer basket (see note 5). Leave 2cm space between the buns and the side of the steamer.
Start cooking with cold water over a high heat. Turn the heat down to medium-low when the water starts boiling.
Cook for 15-18 minutes.
Serving with a dipping sauce
Serve them warm, on their own or with some dipping sauce (find inspirations in my post Six dumpling sauces).
Storage & reheat
You can freeze cooked buns. Leave to defrost in the fridge then steam for 8 minutes to warm up, or steam for 15 minutes without defrosting.
Video
Notes
1. If you don’t have easy access to cake flour, you can mix 250g all purpose flour with 50g cornstarch. Sift before using.2. Use cooking oil which doesn't have a strong taste, such as rapeseeds, sunflower, canola, vegetable, etc.3. The flour water ratio may vary slightly depending on the brand of your flour. Please feel free to adjust.4. You may use a stand mixer with a dough hook instead. Knead for 10 minutes or so on a low speed.5. If you use a metal steamer, you also can brush a thin layer of oil before placing the bao buns.