Here's the supplies, makes one big portion.
Preheat oven to 300 F
Take your fish and rub it down with some flour. It should naturally cling to the wet fish.
Put a significant amount of oil in a skillet and heat on high/medium.
When hot, slap that fillet down in there scale side down.
add some salt/pepper on top if you like. You might have to cover it as the oil can jump out of the skillet quite easily. Let this cook for 5 minutes undisturbed.
Meanwhile, prep a dish for the oven.
After 5 minutes of cooking, the fish should be browned on the bottom. Place this side up on the oven tray and add more salt/pepper.
Stick it in the oven!
After you put the fish in the oven, throw the chopped onion into the same pan you browned the fish in. Add more oil if need be.
Let these cook for about 2 minutes so they can just brown slightly.
After this 2 minutes, add the chickpeas (with juice) to the skillet and add half the sherry (or water).
Turn the heat up to high, and cook for 5 minutes or until just about all the liquid as evaporated out. The chickpeas should turn slightly brown.
If after 5 minutes you still have too much liquid, drain some of it off and return the pan to heat. Add the garlic and some salt/pepper and the rest of the sherry. Cook a bit more if necessary.
By this time, about 10 minutes, the fish should be done in the oven. Judge it yourself, but go ahead and take it out if it looks good and flaky.
Serve the fish on top of the beans. Garnish with the fresh parsley/basil. (I realized I didn't have any, but I did have some grape tomatoes and cucumbers I needed to get rid of!).