After making the monkfish karaage 唐揚げ, I made the remaining monkfish fillet into this dish the next day.
I made medallions of fish a bit less than 1 inch thick. I then marinated them in olive oil, lemon juice and 3-4 fat cloves of crushed garlic for 24 hours. Just before cooking, I removed the excess moisture from the surface of the medallions and lightly seasoned them with salt and pepper. In a frying pan on a medium flame, I added olive oil, and crushed garlic from the marinade and fried it until it became fragrant and slightly brown. I took the garlic out and set aside. I added the medallions of monkfish and cook them for 3-4 minutes and flipped them over. At this point, I added previously blanched Bok Choy which was cut into a bite sized pieces to the center of the pan, moving the medallions to the periphery to make room for the Bok Choy. I then put two thin pats of cold butter on the top of the Bok Choy and cooked it for another 3-4 minutes. The butter will melt very slowly. As the fish was about to finish cooking, I mixed the Bok Choy and butter and added just a small amount (1 tsp) of soy sauce and also add skinned Campari tomatoes to the pan for another minute or so and, at the very last moment, added back the garlic.