Prepare the Salsa Verde

In a food processor or blender, combine the fresh parsley, rinsed capers, garlic clove, Dijon mustard, white wine vinegar, and lemon juice. If you're going for a more robust flavor, add the optional anchovy fillet at this stage.

Pulse until all ingredients are finely chopped but not pureed.

Slowly drizzle in the extra virgin olive oil while blending until the sauce reaches a smooth, slightly chunky consistency.

Season with salt and pepper to taste. Adjust the balance of vinegar and olive oil based on personal preference. Set aside to let the flavors meld while you cook the mackerel.

Cook the Mackerel

Heat a grill pan over medium heat and brush with a small amount of olive oil.

Season the mackerel fillets with salt and pepper on both sides.

Place the mackerel fillets, skin side down, on the heated grill pan. Cook for about 3-4 minutes on each side, or until the skin is crispy and the fish is cooked through but still tender. Be careful not to overcook, as mackerel can become dry.

Once done, remove the mackerel from the heat and let it rest for 5-10 minutes.

Serve

Transfer the mackerel fillets to a serving dish and generously spoon the salsa verde over the top.

Garnish with fresh basil and lemon wedges for an extra burst of flavor.

Serve with a side of roasted vegetables, boiled potatoes, or even a light salad.