Ingredients:

  • 4 Halibut Fillets (approx. 6 oz each, 1–1.5 inches thick)
  • 3 Tbsp Extra Virgin Olive Oil
  • 1 tsp Freshly Grated Lemon Zest (from one large lemon)
  • 2 cloves Garlic (finely minced or pressed)
  • 1 tsp Fresh Thyme Leaves (stripped from the stem)
  • 1 tsp Kosher Salt
  • 1/2 tsp Freshly Ground Black Pepper
  • Neutral High-Heat Oil (e.g., grapeseed or canola, as needed for oiling grates)
  • 4 Tbsp (1/4 cup) Unsalted Butter (cold, cut into cubes)
  • 3 Fresh Thyme Sprigs
  • 2 Tbsp Freshly Squeezed Lemon Juice
  • 1/4 tsp Kosher Salt (for finishing butter)

Instructions:

  1. Pat the Fish Dry: Gently pat the halibut fillets very dry using paper towels. This is vital for achieving a good sear and preventing sticking.
  2. Prepare the Marinade: In a small bowl, combine the 3 Tbsp olive oil, lemon zest, minced garlic, 1 tsp thyme leaves, salt, and pepper. Whisk briefly. Brush the marinade evenly over all sides of the halibut fillets. Cover and refrigerate for no more than 30 minutes.
  3. Make the Finishing Butter: Combine the cubed unsalted butter, 3 sprigs of thyme, lemon juice, and salt in a small saucepan. Place over very low heat just until the butter is melted and warmed through. Keep warm (do not boil or brown).
  4. Preheat the Grill: Heat the grill to medium-high heat (about 450°F / 230°C). Clean the grates thoroughly with a stiff brush.
  5. Oil the Grates: Using tongs and a paper towel dipped in high-heat neutral oil (grapeseed/canola), wipe the hot, clean grates generously until they gleam.
  6. Place the Halibut: Place the halibut fillets directly over the hottest part of the grill. If the skin is on, place it skin-side down first.
  7. Sear and Wait: Close the lid and cook undisturbed for 4–5 minutes. Do not attempt to flip early. Wait until the fish naturally releases from the grill.
  8. Flip the Fish and Finish Cooking: Using a thin-edged metal spatula, gently slide beneath the fish and flip it carefully. Continue grilling for another 3–5 minutes on the second side, moving the fish to the cooler zone (indirect heat) if the outside is browning too quickly.
  9. Check Doneness: Insert an instant-read thermometer into the thickest part of the fillet. Remove the fish from the grill immediately when the internal temperature reaches 135–140°F (57–60°C).
  10. Rest and Serve: Transfer the grilled halibut to a warm plate or cutting board. Tent loosely with foil and let rest for 3–5 minutes. Remove the thyme sprigs from the finishing butter, then spoon a generous amount of the warm butter over each fillet and serve immediately.