Method:

Step 1: Preheat the Oven

Preheat your oven to 400°F (200°C). This will allow the mackerel to cook evenly and crisp up nicely.

Step 2: Prepare the Baking Dish

Lightly grease a baking dish with olive oil or line it with parchment paper. This step helps prevent the mackerel from sticking while baking.

Step 3: Season the Fish

Place the mackerel fillets in the prepared baking dish. Drizzle olive oil over the fillets, then season with salt, pepper, and the minced garlic. Sprinkle the lemon zest evenly on top of the fish, and drizzle the lemon juice over the fillets. If you like, add some fresh thyme or rosemary on top for an extra touch of flavor.

Step 4: Add the Onions (Optional)

For a more aromatic and slightly sweet flavor, scatter thinly sliced onions around the mackerel fillets. This adds a great depth of flavor to the dish.

Step 5: Bake the Mackerel

Cover the baking dish loosely with aluminum foil and place it in the preheated oven. Bake the fish for about 20 minutes. Then, remove the foil and bake for an additional 5–10 minutes to let the fish crisp up and brown slightly on top.

Step 6: Serve

Once the mackerel is cooked through and flakes easily with a fork, remove it from the oven. Let it rest for 5 minutes. Then, garnish with freshly chopped parsley and serve with your favorite side dish (like roasted vegetables, steamed rice, or a light salad).

Variations:

Add vegetables: You can add sliced tomatoes, zucchini, or bell peppers around the fish for more flavor and texture.

Spicy version: Add a pinch of red pepper flakes or a small diced chili to bring some heat to the dish.

Herb variations: Try different fresh herbs like oregano, basil, or dill instead of parsley or thyme for a different taste profile.

Vegan version: If you are looking for a plant-based alternative, try using a firm vegetable like cauliflower steaks or thick slices of eggplant as a base for the recipe.