Combine garlic, oil, soy sauce, oyster sauce, fish sauce, sugar, black pepper, and lime juice in a small shallow dish. Whisk to combine. Transfer in the steak and toss it in the marinade until it's well coated. Poke steak all over with a fork to help the marinade penetrate and spoon some marinade from the sides on top of the steak as well.
Wrap dish and refrigerate for a minimum of 4 to 6 hours, preferably overnight. Flip the steak over occasionally while marinating if possible.
For the dipping sauce, add raw rice to a small dry pan placed over medium heat. Toast rice while stirring and tossing until it’s a deep golden brown color. Remove pan from heat and transfer toasted rice into a mortar and pestle. Let rice cool for a couple minutes, then grind into a slightly coarse powder. Reserve until needed.
Combine tamarind paste, shallot, cilantro, chili flakes, sambal, fish sauce, lime juice, white sugar, brown sugar, and water (if needed) in a small bowl. Stir in toasted rice powder, reserving about 1 teaspoon for the garnish if desired. Whisk dipping sauce ingredients together until well combined and refrigerate until needed.
Remove steak from the marinade and allow excess marinade to drip off..
Preheat an outdoor grill for high heat and lightly oil the grate.
Grill your steak to a medium doneness for best results, about 3 minutes per side.
Remove from grill and let the steak rest for 5 minutes. Slice into thin strips. Fan the strips out for a nicer presentation, and serve with the dipping sauce, garnish with the reserved toasted rice powder.
