Pulverize the garlic, black pepper, and coriander roots until smooth. Rub the beef with the mixture after stirring in the oil and oyster sauce. Overnight marinate.
Let tomatoes and cucumbers soak in the seafood dressing for 30 minutes.
In a large nonstick frying pan, heat the oil, then grill the sirloins on both sides to the desired degree of doneness. Slice thinly after resting for five minutes on a wire rack.
Arrange tomato slices, cucumber slices, and slices of grilled meat on top of each platter.
Drizzle red seafood dipping sauce over the dish and garnish with celery, onion, and red finger chili. Serve
Put all the ingredients for the dipping sauce in a blender. Blend them until smooth.