Start by preparing the white radish. In a large wok filled with boiling water, boil the white radish for a few minutes to get rid of the bitterness. Scoop out and set aside.
In a clean wok, add in the boiled white radish, 3 cups of water, and the brown slab sugar piece. Bring to a boil and cook for 10 minutes. Make sure the sugar has completely dissolved. Remove from the wok and set aside everything (including all the liquid - you’re going to need this later).
Curry Paste Mixture: In a bowl, mix together all the ingredients until combined. Set aside.
In a wok with heated neutral oil over medium-high heat, stir fry the garlic and shallots until fragrant. Add in the curry paste mixture and keep on stir frying it for a few minutes to allow the flavours to come out. Add in the Chinese cooking wine and mix until the liquid has evaporated. Add back in the cooked white radish and the liquid that was set aside earlier. Add in the beef omasum, fishballs, and beef balls and give everything a good mix. Once it comes to a boil, lower the heat to medium-high, and continue cooking for 5-7 minutes, or just until everything is cooked through.
Season the curry by adding salt, sugar, oyster sauce, and soy sauce. Mix in the cornstarch slurry (mix the 2 ingredients in a bowl first) to thicken the sauce a little. The fishballs and beef balls should be finished with a glossy and shiny look. Plate and enjoy!