Butter makes everything better. And that is VERY true in this dish. If you only have olive oil on hand, feel free to sub that for the butter. However, the melted butter combined with the olive oil is going to give this fish the MOST decadent, melt in your mouth flavor and texture. So don't skip it!

Green olives are a great substitute for capers. I usually keep capers on hand because their briny bite is one of my favorite things to add to any fish or pasta dish. But in a pinch, green olives would be a great sub! I'd add slightly more green olives in this recipe to match the bold flavor that the capers deliver.

Don't overcook the fish! This seems like a no-brainer, but sometimes I think people get really stuck on following a recipe to the T and forget to use their judgment. Everyone's oven cooks differently. Everyone's fish fillet may be of a different shape or thickness. Everyone's baking dish heats up differently. Use your judgment when it comes to baking time here. As soon as the fish starts to flake easily, it's done!