I can't remember where the inspiration for this recipe originated, most likely a food magazine from the 1990's. I've never written it down until posting, Google search does not come up with any overlap.
It's changed over the years for me, using cilantro stems, and using cherry tomatoes for the salsa base.
For quicker use, I've used chunky jarred salsa instead of fresh product, but of course the fresh is much better. I normally use the "Christmas grape" cherry tomatoes when I make it fresh.
You can use this sauce with chicken cutlets pounded flat and treated in the same manner. Cilantro is very optional at my house, however, for cilantro haters chopped Cilantro stems--no leaf--will give you the flavor without the cilantro reaction that some find distasteful. You can substitute chopped parsley or omit.
Any firm fish can be used, but the cornmeal and strong tones of the catfish work well with the flavorful salsa butter. - Sam1148 —Sam1148
Test Kitchen Notes
Sam1148 uses catfish for this simple stunner, but really you could use any mild, white fish. A light cornmeal coating gives the fish a delicate crunch, and while you may be skeptical of the scant amount of lime juice and garlic you use to marinate the fish, it manages to shine through. But the salsa is the real star of the show: plump cherry tomatoes cook down with onion, tequila, jalapeno, cilantro and lime, and after you add a knob of butter, you've got a silky, spicy, vibrant sauce for the crisp, fresh fish. -A&M —The Editors
Mix the olive oil, lime juice, and garlic with the fish (or chicken) in a non-reactive bowl and let rest for 1 hour.
Heat 1 tablespoon of olive oil in a large saute pan over medium heat. Add tomatoes, jalapeno, onion, garlic, cilantro stems, and lime zest and begin cooking it down, stirring occasionally. It should be well cooked down and bright red, and the juices should be a bit reduced. Add stock or water to the salsa if needed to keep it from sticking. Add tequila; I go for 2 shots of tequila and add a bit more lime zest and lime juice for mine. Cook some more until the juices are reduced.
Heat a thin layer of butter and/or oil in another large saute pan over medium high heat. Season the corn meal with salt and pepper, dredge the fish and fry in the olive oil or butter until golden brown on both sides, flipping once, about 1-2 minutes. Remove to a warm oven while you finish the sauce.
To finish: Stir in a few tablespoons of softened butter off heat. Do this off the heat as you want the butter to make a creamy sauce. Serve over the fish. Garnish with chopped green onions and serve with lime wedges. Note: A nice crunchy finishing salt as an option for guests can be served along side the dish.