Preheat the oven to 200°C (400°F). Preheating ensures the oven is hot enough to begin cooking the fish immediately so the exterior sets and the interior cooks gently—this helps prevent overcooking.

Pat the cod fillets dry with paper towels and transfer to a shallow dish. Drying the fish removes surface moisture so the marinade clings and the fish roasts instead of steaming.

Make the citrus-caper marinade: in a small bowl whisk together 4 tbsp lemon juice, 2 tsp lemon zest (for the marinade), 4 tsp drained capers (roughly chopped if large), 4 tsp extra-virgin olive oil (drizzle amount), a generous pinch of flaky sea salt and several grinds of cracked black pepper. Pour half of this mixture over the cod, turning to coat. Reserve the remaining half for finishing. Marinate for 10–15 minutes (no more than 20) — the acid brightens the fish but too long will 'cook' the delicate flesh.

While the fish marinates, prepare the couscous: melt 1 tbsp butter and 1 tbsp olive oil in a medium sauté pan over medium heat. Add the dry Israeli couscous and toast, stirring frequently, until the pearls are lightly golden and smell nutty, 3–4 minutes. Toasting develops a deeper, nuttier flavor and helps keep the pearls separate when cooked.

Add the minced garlic to the toasted couscous and cook for 30 seconds until fragrant—this softens the raw edge of garlic and infuses the oil. Immediately pour in the 720 ml hot stock, bring to a simmer, then reduce heat to low, cover, and cook until the pearls are tender and most of the liquid is absorbed, about 8–10 minutes (check package directions and adjust as needed).

While the couscous simmers, wilt the Swiss chard: heat a wide skillet over medium heat with 1 tbsp olive oil (included above). Add the minced garlic and cook 30–45 seconds until fragrant (don’t brown). Add the chopped chard, toss, then add a splash (1–2 tbsp) of stock or water, cover and let steam-wilt for 2–3 minutes until tender but bright green. Remove cover and cook another minute to evaporate excess liquid. Season with salt and pepper and a squeeze of lemon juice from the reserved lemon (this brightens the greens). Wilted chard adds color, vegetal sweetness and fiber to balance the dish.

When couscous is done, remove from heat and fluff with a fork. Stir in 4 tbsp chopped parsley, the remaining reserved lemon-caper mixture (if you like pronounced caper pockets you can reserve a teaspoon for the fish finish), 1 tbsp butter and the 1 tsp finishing lemon zest. The butter and parsley add silkiness and fresh herb lift; finish zest adds an immediate citrus perfume.

Arrange the marinated cod fillets in a single layer on a parchment-lined baking sheet or shallow baking dish. Drizzle the reserved 4 tsp olive oil over each fillet (this encourages browning and keeps the top glossy). Scatter the remaining capers over the fillets and lightly season with flaky sea salt and cracked black pepper.

Bake in the preheated oven until the cod is opaque and flakes easily with a fork, about 10–12 minutes depending on thickness (check at 8 minutes for thinner fillets). Baking at moderately high heat cooks the fish quickly and evenly; removing it as soon as it flakes guarantees moist, tender flesh.

Remove the fish from the oven and let rest for 2 minutes — brief resting lets the juices redistribute. Taste the couscous and greens for seasoning and adjust with flaky salt, pepper, or another squeeze of lemon if needed.

To serve: spoon a bed of herbed Israeli couscous onto each plate, top with a portion of wilted Swiss chard, and place a baked citrus-caper cod fillet on top. Finish with a final sprinkle of the 1 tsp finishing lemon zest, a few extra chopped parsley leaves for color, and an optional extra drizzle of good olive oil.

Serve immediately. Encourage guests to squeeze a little more lemon over their fish at the table for bright finish—acid will lift the caper-salty and buttery notes.