Cut the NY strip steak into 2-inch cubes. Add to a bowl with the minced garlic, brown sugar, cornstarch, black pepper, oyster sauce, fish sauce, soy sauce, and neutral oil. Toss well to coat. Marinate for 10 minutes while you prep everything else.

Slice your cucumber and tomato and arrange them on a serving plate. Cut the lime into wedges and set aside.

In a small bowl, combine the dark soy sauce and oyster sauce. Set aside. This goes in fast once the beef is cooked.

Heat a large skillet or wok over high heat. Add the avocado oil. Once hot and shimmering, sear the beef in batches, 2 minutes per side. Do not crowd the pan, or the beef will steam instead of sear. Work in two or three rounds if needed.

Once all the beef is seared, return it to the pan. Add the thickly sliced onions and pour in the sauce. Shake and toss the pan continuously, coating everything in the sauce. This is literally where the name "shaking beef" comes from.

Remove the pan from the heat. Add the cold butter and toss until melted and glossy.

Plate over steamed rice. Serve with all or any toppings you want. I served mine with pickled red onions, the tomato cucumber salad, and fried garlic on top of the rice.