Grilled Onion-Butter Cod

By
Derrick Riches
Derrick Riches
Derrick Riches
Derrick Riches is a grilling and barbecue expert. He has written two cookbooks.
Learn about The Spruce Eats' Editorial Process
Updated on 12/3/21
Tested by
Colleen Graham
Photo of Colleen Graham
Tested by Colleen Graham
Freelance writer and cocktail book author Colleen Graham is a seasoned mixologist who loves sharing her knowledge of spirits and passion for preparing drinks.
Learn about The Spruce Eats' Editorial Process
Prep: 10 mins
Cook: 15 mins
Total: 25 mins
Servings: 4 servings

This delicious grilled cod has a fantastic buttery flavor and texture. The onion and white wine combine with the butter to create a complexly flavored sauce that, although simple to make, will taste as if you spent a lot of time and effort making it. When served with grilled potatoes or vegetables of your choice, this dish makes the perfect weeknight meal or an impressive entrée for a special gathering. 

Cooking fish fillets on the grill can be a bit tricky, but there are some tips you can follow to avoid problems. To prevent the fish from falling apart or slipping through the grates, choose a fish that is thick and firm, such as cod, as it will hold up well on a grill. Also, make sure the grates are clean and thoroughly greased just before adding the fillets. The grill should also be nice and hot, and, finally, use a large grilling spatula and only flip the fish once, leaving it alone to cook the rest of the time.

Grilled butter onion cod recipe

The Spruce / Julia Hartbeck

"I’m quite reluctant to grill fish directly on the grates, but this recipe gave me the confidence to try. A clean, well-oiled grill is key. This recipe makes a generous quantity of sauce, so you may have some leftover. The flavor is excellent, and it’s a simple recipe worth adding to your grilling repertoire." —Colleen Graham

Grilled Onion Butter Cod Tester Image
A Note From Our Recipe Tester

Ingredients

  • 1/4 cup (4 tablespoons) unsalted butter

  • 1 small yellow onion, finely chopped

  • 4 (6-ounce) cod fillets

  • 1/4 cup white wine

  • 1 tablespoon olive oil

  • 1/2 teaspoon salt, more to taste

  • 1/2 teaspoon freshly ground black pepper

  • Lemon wedges, for serving

Steps to Make It

  1. Gather the ingredients. Preheat the grill to medium-high heat.

    Ingredients for grilled onion butter cod recipe
    The Spruce / Julia Hartbeck

  2. In a small skillet, melt the butter. Add the onions and cook for 1 to 2 minutes, until translucent and aromatic.

    Melt butter
    The Spruce / Julia Hartbeck

  3. Add the white wine and simmer for 3 minutes. Remove from the heat and let cool for 5 minutes.

    Add white wine
    The Spruce / Julia Hartbeck

  4. Brush the fish fillets with the olive oil and sprinkle with salt and pepper. Place the fish on a well-oiled grill rack, close the lid, and cook for 8 minutes.

    Brush fish fillets
    The Spruce / Julia Hartbeck

  5. Baste the cod with the butter sauce and then carefully flip over the fish. Cook for 6 to 7 minutes—basting the fish a total of 2 to 3 times—until the fish is opaque, flakes easily with a fork, and reaches an internal temperature of 145 F.

    Baste cod
    The Spruce / Julia Hartbeck

  6. Remove the cod from the grill. Spoon some of the sauce on top of each fillet and serve with lemon wedges. Enjoy.

    Cod onion
    The Spruce / Julia Hartbeck

Other Methods for Grilling Fish

If you are apprehensive to cook the fish directly on the grill grates, there are a few alternatives. You can place the fillets in a grilling fish basket, grill it on a wooden plank, or wrap the fish in a foil packet (the fish will have a smoky grilled flavor but not get any grill marks). Using an indoor grill is also a great option.

Tips

  • To grease the grill grate, wipe it with an oil-soaked paper towel held with tongs.
  • Make sure the grill is very hot before adding the fish; the cod will stick to cooler grates.
  • It is always best to grill with the lid down. Every time you open the lid, you're releasing heat and potentially increasing the cooking time.
  • Make sure not to overcook the fish; not only will it be dry but will also more likely fall apart on the grill.
  • Store any leftover cooked fish in an airtight container in the refrigerator for up to three days. You can also flake the leftovers and add them to soups or stews. 

Recipe Variations

  • This recipe works well with other varieties of fish. Good substitutes for cod are black cod, grouper, haddock, hake, mahi-mahi, pollack, and striped bass.
  • Substitute the onion with shallot. You might need two shallots to equal the size of one onion.
  • For added brightness and flavor, add chopped fresh herbs to the butter. Try basil, tarragon, parsley, or dill.
Nutrition Facts (per serving)
402 Calories
17g Fat
24g Carbs
41g Protein
×
Nutrition Facts
Servings: 4
Amount per serving
Calories 402
% Daily Value*
Total Fat 17g 22%
Saturated Fat 8g 40%
Cholesterol 124mg 41%
Sodium 404mg 18%
Total Carbohydrate 24g 9%
Dietary Fiber 6g 21%
Total Sugars 9g
Protein 41g
Vitamin C 110mg 548%
Calcium 83mg 6%
Iron 2mg 12%
Potassium 780mg 17%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)