Cooking fish at a low temperature in a covered pot is a nearly foolproof way to achieve perfectly cooked fish, since the heavy Dutch oven holds in moisture and allows the fish to cook through gently and evenly. This method is also a wonderful way to concentrate flavor, meaning that a minimum of ingredients can make a big impact. We started by browning sliced garlic in oil, which mellowed its flavor and infused the dish with warm aromatic notes. Cherry tomatoes, which are of reliable quality year-round, became soft and sweet with the gentle cooking. Capers provided briny bites, and thyme gave the dish an herbal base note. Browning the halibut was unnecessary; it didn’t contribute much to the flavor, and the fish’s texture was better without it. While the halibut rested, we finished the sauce by cooking off some of the excess liquid on the stovetop. Sea bass and swordfish steaks are good substitutes for the halibut.
Ingredients
- ¼ cup extra-virgin olive oil
- 2 garlic cloves, sliced thin
- ⅛ teaspoon red pepper flakes
- Salt and pepper
- 12 ounces cherry tomatoes, quartered
- 1 tablespoon capers, rinsed
- 1 teaspoon minced fresh thyme or ¼ teaspoon dried
- 2 (1¼-pound) skin-on full halibut steaks, about 1¼ inches thick and 10 to 12 inches long, trimmed
- Adjust oven rack to lowest position and heat oven to 250 degrees. Heat 2 tablespoons oil in Dutch oven over medium-low heat until shimmering. Add garlic, pepper flakes, and pinch of salt and cook until garlic is light golden, 2 to 4 minutes. Off heat, stir in tomatoes, capers, and thyme.
- Season steaks with salt and pepper and lay on top of tomatoes. Cover, transfer pot to oven, and cook until halibut flakes apart when gently prodded with paring knife and registers 140 degrees, 35 to 40 minutes.
- Remove pot from oven. Using 2 thin spatulas, transfer steaks to cutting board, tent with aluminum foil, and let rest while finishing sauce. Bring tomato mixture to simmer over medium-high heat and cook until slightly thickened, about 2 minutes. Off heat, stir in remaining 2 tablespoons oil and season with salt and pepper to taste.
- Remove skin from steaks and separate quadrants of meat from bone by slipping spatula gently between them. Serve halibut with sauce.
