01 - In a large pot, combine beef cubes, water, bay leaves, kaffir lime leaves, lemongrass, and salt. Bring to a boil over high heat, then reduce heat to low and simmer for 45 to 60 minutes until tender. Remove beef from broth, reserving the stock for the sauce.
02 - Place shallots, garlic, chilies, candlenuts, coriander, cumin, turmeric, ginger, galangal, and white pepper in a blender. Process until a smooth paste forms, scraping down sides as needed.
03 - Thread cooked beef onto soaked bamboo skewers. Grill over hot charcoal or a preheated grill pan for 4 to 6 minutes, turning frequently and basting with a little oil, until slightly charred on all sides.
04 - Heat oil in a saucepan over medium heat. Add the spice paste and sauté for 3 to 4 minutes until fragrant and oil begins to separate. Pour in the reserved beef stock, salt, and sugar. Bring to a gentle simmer.
05 - Whisk rice flour with 2 tablespoons of water in a small bowl until smooth. Slowly pour the slurry into the simmering sauce while stirring constantly. Continue cooking for 3 to 4 minutes until thickened and smooth.
06 - Arrange beef skewers on a serving plate. Pour the hot sauce generously over the skewers. Garnish with fried shallots and serve with sliced rice cake on the side if desired.