Grind together white pepper, cumin, coriander seeds, ginger, shallot, and candlenuts in a food processor or mortar and pestle until a smooth paste is formed.
In a big saucepan, warm up the vegetable oil over medium heat. Add the spice paste and cook for 3–4 minutes, or until aromatic. Cook the chopped beef or oxtail in the saucepan until it takes on color.
Tear the lemongrass stalk into pieces and add it to the saucepan with the star anise, galangal, bay, and kaffir lime leaves. Allow the aromatics to seep into the meat by giving it a good stir to integrate.
Fill the saucepan with enough water to cover the steak. After bringing everything to a boil, turn down the heat. Simmer for one to two hours, or until the meat is cooked and the flavours are well combined. Remove any contaminants that surface by wiping them off.
After the meat is soft, taste it and adjust the amount of salt and sugar in the soup. Taste and adjust the seasoning.
Ladle the soup into bowls for serving. Add bean sprouts, fried onions, chopped tomatoes, and celery leaves as garnish. Serve hot with your choice of side dish or over steaming rice. Savour the rich and savoury Soto Daging, an Indonesian beef soup!