Caramelized onions are one of those ingredients that deliver so much more than the sum of their parts. They just require patience and low heat, and if you are really impatient you can cheat with a little molasses, brown sugar or balsamic vinegar to expedite the sweetening and browning process.
I was preparing cod for dinner recently and did not have a lot to work with in the pantry, but I always have onions. I mulled over the “low and slow” method of fish cookery and thought caramelized onions would be a great way to keep the cod from drying out while infusing a deliciously complex flavor with the simplest ingredient list.
We served the fish with quinoa and salad, but it really goes with most anything. I used cod because that was what I had on hand, but this would work with bass, salmon, halibut, haddock, flounder, fluke, snapper, et cetera.
Caramelized Onion Cod
1 medium onion, sliced
1 tablespoon oil
Salt and pepper to taste
¾ pound cod filet
Fresh parsley to garnish, if desired
In an ovenproof skillet, heat the oil and sauté the onions with salt and pepper over medium heat until they begin to sweat, stirring occasionally. Reduce the heat to low and allow the onions to cook slowly, stirring occasionally, until they are light brown, about 30 minutes.
While the onions cook, heat your oven to 275 degrees F. When lightly brown, move the onions to the edges of the pan and place the fish in the center. Spoon the onions over the fish, coating evenly, and place the pan in the oven; bake for 25 minutes until the fish is cooked through and opaque throughout.
Garnish with parsley if desired, and serve immediately.