I’ve seen chefs use this technique on TV but never really understood it. It didn’t sound very healthy! There was an article about it in the recent issue of Cook’s Illustrated , so I decided to try it. The article says that this cooking method is not greasy and unhealthy like you might think. The high water content of the fish prevents the oil from absorbing into it. Cooking it at a low temp in the oil keeps it moist and keeps the oil out.
I placed 3/4 cup olive oil in an ovenproof skillet and placed half an onion in the center (the onion helps raise the level of the oil so you don’t need to use as much and also, I think, adds a little flavor). Heat the oil on the stove to 180 degrees (this happens quickly). Place 2 seasoned fillets of white fish (I used halibut, about 6 ounces each) in the pan and spoon oil over the top. Cover the pan and place in a 250 degree oven for 15 minutes. Remove from the oven and flip the fish. Cover and return to the oven for about 10-14 minutes, until it reaches 130 degrees. Mine was done in 10 minutes.
The recipe in the article involved frying some artichoke hearts and then using some of the oil from the fish to make a vinaigrette. I was out of artichoke hearts (thought I had some, but couldn’t find them- how often does this happen to you?), but I did use some of the oil with a handful of cherry tomatoes, blueberry vinegar, 2 garlic cloves, and a pinch of sugar and salt to make a quick sauce in the food processor.
I’m glad I tried this method, but don’t know if I would do it again. The fish was very moist and held together nicely, however, I missed the flavor you get when you grill, pan-fry, or bake fish in a sauce. It was really just like poaching the fish in water I think. Even with the sauce I made, it was just a bit bland. It was also a pain to be taking the fish in and out of oven.