1. Season the Halibut well with salt and pepper.
2. Sear in a pan with hot oil until cooked.
3. In a large wok or skillet, heat the remaining canola oil and quickly stirfry the ginger, garlic and scallions. Add the bok choi and stirfry quickly until it just begins to wilt. Add the corn kernels and cook for another minute. Drizzle in the oyster sauce and mix to coat evenly.
4. Serve the seared fish over the stirfried vegetables.