Make a dry caramel with the sugar over medium heat.
55 g sugar
Once the caramel is ready, carefully pour in the water (watch out for steam; turn on the range hood if you like). The caramel will dissolve into the water.
0.5 cup water
Add the frozen lotus root to the wok and cover with enough water to fully submerge it.
500 g frozen lotus root
Add the vinegar, soy sauce, garlic, and neutral oil.
Reduce the heat to low and cook for 40 minutes. Lift the lid occasionally and turn the slices so they brown evenly. Add more water if needed.
Add the sugar and stir to combine. Cover and simmer for another 20 minutes.
100 g sugar
Uncover and increase the heat to medium-high. Stir and gently turn the lotus root, then braise for 10 to 12 minutes, until each slice is glossy and almost all the liquid has evaporated.
Braised lotus root
Remove from the heat and stir in the sesame oil. Sprinkle with sesame seeds.
2 teaspoons sesame oil
Notes
Store any leftovers in an airtight container in the refrigerator for up to 2 weeks.