Pre-heat the pan to medium heat, add the coriander seed, cumin seed, lemongrass, onion red, garlic, dry chili with a little oil. Transfer this spice mix to a food processor and blend it with turmeric powder, salt, sugar, and black pepper.
Coat the 2 beef pieces with this blended mixture and leave it in the fridge for ½ hour to marinate.
To prepare tomato and chili relishes, mix the onion, tomato, red chili, cili padi, shrimp paste, tamarind juice, palm sugar and salt
Pre-heat the pan over high heat, add some cooking oil and place the beef on one side and sear for 3-4 minutes. Turn the beef on the other side and sear for 3-4 minutes. Repeat with the second piece of marinated beef.
Once the beef is cooked, rest beef for 2 minutes before slicing it. Serve the sliced beef with the relishes and steamed fragrant rice.