Season both sides of fish. Add olive oil and butter to a skillet. On medium to high heat add fish to skillet. Get a good sear on the fish, about 3 minutes. Carefully flip the fish and finish cooking, another 2-3 minutes. I usually cover the skillet if cooking inside to prevent splatter. Fish should have a 120°F internal temperature and start to flake.

In the same skillet add butter and melt on low heat. Add onions and peppers and soften, about 2 minutes. Add garlic and cook for 30 seconds.

Whisk in flour to make a roux. Add heavy cream, chicken broth, hot sauce, and Cajun seasoning. Stir and bring to a boil. Reduce heat and simmer for 5 minutes. Taste and add addition seasoning or salt if needed. If too thick add some broth, and if too thin simmer a little longer.