01 - Pat the cod fillets dry with paper towels. Season both sides generously with sea salt and freshly ground black pepper.
02 - Heat olive oil in a large non-stick or cast-iron skillet over medium-high heat. Add the cod fillets and sear for 2–3 minutes per side, until lightly golden and almost cooked through. Transfer to a plate and keep warm.
03 - Reduce the heat to medium. In the same skillet, add the finely minced garlic and sauté for about 30 seconds until fragrant.
04 - Stir in the fresh lemon juice, lemon zest, honey (or maple syrup), and Dijon mustard. Bring to a gentle simmer for 2 minutes, stirring constantly to combine.
05 - If using butter, whisk it into the glaze until fully melted and emulsified into a smooth sauce.
06 - Return the cod fillets to the skillet, spooning the glaze generously over the top. Simmer gently for 2–3 minutes until the fish is cooked through and the glaze has thickened slightly.
07 - Sprinkle with chopped parsley, garnish with lemon slices, and serve immediately.