Egg Custard Buns (Nai Wong Bao / Liu Sha Bao) is a popular Cantonese dim sum marked by ultra-smooth, soft bun with luscious, creamy salted egg yolk filling. Turns out, butternut squash is an excellent substitute for egg yolks, making these vegan-friendly and taste just as good!
They are so irresistibly good. Borderline addictive. I can’t name many things in this world more satisfying than biting into a perfectly soft steamed bun and feeling that buttery, luscious filling ooze out…
STEP BY STEP GUIDE
#1: Roast the Butternut Squash. For this recipe, I’m using butternut squash to replace salted egg yolks. Pre-heat the oven to 400 degrees F (200 degrees C). Start by splitting the squash in half and scooping out all the seeds & fibers. Place the squash flesh-side down on a parchment-lined baking tray. Roast the squash for 45-55 minutes, or until completely tender. Be careful not to cause too much caramelization and browning as we want the flesh to remain brightly orange (to replace the salted egg yolks).
#2: Make the Custard Filling. Once the butternut squash has cooled completely, remove the flesh & mash with a fork. Run the puree through a fine mesh sieve — you want it to be completely smooth. In a bowl, combine all the filling ingredients and whisk very well to combine. Add the mixture to a pot, and bring to a boil while stirring constantly until thickened. Place in the freezer for around 30 minutes to firm up. To know if the filling is firm enough, if you run your fork through it, it should crumble up and shouldn’t stick to your hands when you try to shape it. Run a fork through the filling to break it all up & roll into evenly sized balls that are 18-20 grams each (see a later step for visuals). You should get about 10 balls of custard filling.
Step #3: Make the Dough. On your work surface, mix together flour, sugar, yeast, and baking powder. Make a well in the center and slowly add water, stirring to incorporate. Note: this is a high hydration dough, so it will be sticky at first. You shouldn’t add any additional flour, otherwise your baos will turn out tough. Keep kneading and unsticking all the bits on the counter until the dough is smooth and the counter & your hands are clean.
Step 4: Divide the Dough. Divide the dough into equally sized, 30-35 gram pieces. My entire dough weighed 350 grams at this point, so I divided mine into 10 portions. Roll each portion into balls and set aside, covering loosely with plastic wrap to prevent drying.
Step #5: Make the Buns (video tutorial available on my instagram). Work on one bun at a time. Take one dough ball and roll it out into a rectangular sheet, then fold it over, turn it 90 degrees, and repeat. Repeat this rolling & folding for 5 times. I first saw this done by a Chinese pastry chef — the technique yields a super smooth bun. At the end, roll the dough into a round shape (doesn’t have to be completely round) and place a ball of filling in the middle. I usually keep all the filling in the fridge and take them out one at a time, so they don’t start melting too fast.
Gather the dough to the top. Continue to twist until the top is sealed and a bit of extra dough remains. Remove the extra dough, turn the bun on its smooth side, and place on a piece of parchment paper.
Step #6: Steam the Buns. Once you have about 5 buns ready, you can steam them as the first batch. First place them (with the parchment paper) into your steamer basket. Cover and let proof for 15-20 minutes, then steam for around 8 minutes. Serve immediately.