I'm just starting to get into cooking with cast iron and this was the first dinner recipe I've made with it. It turned out wonderful! My husband really enjoyed this halibut. I'm sure any kind of white fish would be just as good.
To prepare raita, mix together the sour cream, cucumber, fennel, mint, salt and pepper in a medium bowl. Refrigerate until ready to serve.
To prepare fish, position a rack in the center of the oven and preheat to 375.
Place the sliced fennel in a 10-12" cast iron skillet. Lay the halibut fillets on top of the fennel and drizzle with the olive oil. Scatter the lemon slices, thyme and sea salt over top. Cover with foil and bake until the fish flakes easily when tested with a fork, 15-20 minutes. Serve with Cucumber-Fennel Raita, green salad and crusty bread.