1. Begin by making the marinade in a small saucepan. Heat the shallot, ginger, lime zest, lime juice, lime leaves, silan, mirin, garlic, star anise, black pepper, and soy sauce. Bring the mixture to a boil and keep it for few hours or overnight in the fridge.
2. Brush the beef in olive oil and season well with sesame seeds. Let sit for one hour at room temperature.
3. Heat a pan over high heat and sear the beef in the beef tallow on all sides, about four to six minutes per side.
4. In a saucepan, warm the sugar over medium heat until it dissolves and starts to bubble.
5. Remove saucepan from heat and slowly pour in the coconut liquid.
6. On medium heat, whisk continuously until all of the cream has been incorporated. Sugar will form clumps, but continue swirling and cooking until the mixture thickens and turns a deep amber color like honey (this can take eight to 12 minutes).
7. Cut the beef tallow into cubes. On medium heat, add one cube at the time and let it melt in the caramel sauce.
8. Add cold marinade into the caramel sauce and warm it up. Bring it to a boil, then remove from heat.
9. Slice the steak into even pieces and arrange across a deep plate. Pour the marinade sauce over the beef. Garnish with sprouts and scallions.