Make the brown sugar syrup first by boiling the sugar with 1 cup of water and optional flavorings in a saucepan for one to two minutes. Reduce to lowest heat setting, cover and keep warm.

Place the sweet potato chunks into a large saucepan or pot and add enough water to cover. Gently boil until tender. Drain and allow to cool on a plate lined with paper towels.

Finely grate about 2-3 teaspoons of fresh ginger root. Use a coffee filter or a piece of kitchen muslin to squeeze the ginger juice into a mixing bowl. When the sweet potato is cool enough, transfer to the bowl with the ginger juice and use a clean hand(s) to squeeze and mash the potatoes until smooth. Sprinkle in about 1/4 cup of the rice flour at a time, massaging it in, until the dough resembles a sticky Play-Doh.

Dust a surface (clean counter, cutting board, sheet pan, etc.) with some of the rice flour. Pull the dough into marble-sized pieces, then gently roll each one between your palms until the surface is smooth. Arrange them on the dusted surface as you go. Try to make sure you have multiples of Chinese lucky numbers 6, 8, or 9 per guest.

Bring a pot water to boil. In small batches, drop the yuan into the water. They will sink to the bottom (don’t worry if they stick) and when they float to the surface, cook a few minutes longer. Use a slotted spoon and transfer to the pot of brown sugar syrup while you boil the rest of the yuan.

Once all are boiled and soaking in their brown sugar bath, they will keep until dinner is finished or can be served right away by ladling into small bowls with some of the syrup.