The best bake time for halibut is 10 to 15 minutes at 425 degrees. Since halibut has a lower fat content than most fish, you’ll want to keep a close eye on it so it doesn’t dry out in the oven. It’s also not a bad idea to add olive oil or butter to help keep the fish moist as it cooks. You can test your halibut with a fork to tell if it’s done: If the flesh flakes easily with a fork, it’s ready to eat. You can also test the fish with a meat thermometer, looking for a temperature of 130 degrees.