In a pan, add the radish, garlic, ginger, and sauce. Boil over medium high heat until the braising liquid is slightly thickened and the radish becomes soft. Add the onion and chili peppers and boil.
Add the fish, and boil for 4-5 minutes, depending on the thickness of the fish. Carefully flip them over, and boil for another 4-5 minutes, repeatedly spooning the sauce over the fish. Serve with a bowl of rice.