Marinate the Steak: Pat the 250-300g steak completely dry with paper towels. Cut it against the grain into 1cm wide strips. In a bowl, combine the steak strips with 1 tsp cooking oil, 1 tsp light soy sauce, and 3-4g freshly ground black pepper. Toss gently to coat. Let it marinate for 30 minutes at room temperature.

Prepare Components: While the steak marinates, bring a pot of water to a boil. Cook the 200g rice cakes according to package directions (usually 3-5 minutes for fresh/frozen) until softened. Drain and rinse with cold water to stop the cooking and prevent sticking. Set aside. In a small bowl, whisk together all the sauce ingredients: 10g minced garlic, 1 tsp light soy sauce, 1 tsp oyster sauce, 2g black pepper, and 100ml water. Slice the onion into strips if using.

Sear the Steak: Heat a large skillet over high heat. Add 1 tsp of cooking oil. When the oil is hot, add the marinated steak strips in a single layer, working in batches if needed to avoid overcrowding. Let them sear undisturbed for 1 minute to develop a brown crust. Flip and cook for another minute until browned but still tender inside.

Sauté Aromatics: Add the sliced onion (if using). Sauté over medium heat for 1-2 minutes until it begins to soften.

Combine and Simmer: Add the drained rice cakes. Pour the prepared sauce over everything. Bring the sauce to a boil, then reduce the heat to low. Simmer for 2-3 minutes, stirring occasionally, until the sauce has thickened enough to coat the back of a spoon.

Garnish and Serve: Remove from heat. Garnish with 2g toasted sesame seeds and 1g dried parsley flakes if desired. Serve immediately.