Marinate the beef by mixing garlic, oyster sauce, Golden Mountain sauce, and sugar in a bowl. Add beef and coat thoroughly. Cover and refrigerate for at least 2 hours.

Grill the marinated beef on medium-high heat for 5-10 minutes per side until desired doneness is reached. Let it rest for 5 minutes.

Slice the rested beef against the grain into thin strips.

Make the dressing by combining fish sauce, lime juice, chili flakes, and toasted rice powder in a bowl.

Combine sliced beef with dressing and toss gently. Fold in shallots, green onions, mint, cilantro, and kaffir lime leaves.

Serve the salad immediately on a platter, optionally pairing with sticky or jasmine rice and fresh vegetables.