Bring mise en place: pat the cod very dry with paper towels (moisture prevents a good sear), zest and juice the lemons separately, rinse and drain the capers, finely chop the herbs, measure the couscous and have hot stock ready. Dry fish yields a flavorful golden crust; pre-measured ingredients make the finish quick and precise.

Make the couscous base: in a medium saucepan over medium heat, warm 1 tablespoon olive oil and 1 tablespoon butter, add the chopped onion and a pinch of salt, and sweat for 3–4 minutes until translucent but not browned. Sweating softens the onion and releases sweetness; avoid color to keep the couscous bright.

Add minced garlic and 1 teaspoon lemon zest to the onions and cook 30 seconds to bloom the garlic's aromatic oils (don’t let it burn). Add the hot stock and bring to a gentle simmer — hot liquid helps couscous hydrate quickly and evenly.

Remove the pan from the heat, quickly stir in the dry couscous and press it down so all grains contact the hot liquid. Cover tightly and let rest undisturbed for 5 minutes. This steam method hydrates the couscous gently so it stays tender and separate.

Fluff and finish the couscous: with a fork, fluff the couscous to separate grains; drizzle in 1 tablespoon olive oil, the chopped parsley and cilantro, the peas (if frozen, sprinkle them over the hot couscous so residual heat thaws them evenly), 1 tablespoon lemon juice, salt and pepper to taste. Toss gently to combine. Adding oil after fluffing keeps the grains glossy and prevents clumping; herbs and lemon brighten the flavor.

Season the cod: salt and pepper both sides of the fillets and rub with a teaspoon of olive oil. Let rest 5 minutes while the couscous finishes. Salt draws out some moisture; a short rest allows even seasoning and helps form a better crust.

Heat a large nonstick or heavy stainless-steel skillet over medium-high heat until hot (a few drops of water should sizzle away). Add 2 tablespoons olive oil and swirl to coat. A properly heated pan gives immediate contact heat to form a golden sear.

Place the fillets skin-side down if skin-on (or presentation side down if skinless). Press gently with a spatula for 10–15 seconds to ensure even contact. Sear without moving for 3–4 minutes depending on thickness (for 140 g fillets this often yields an opaque edge and a translucent center). The initial undisturbed sear creates a crisp exterior and flavor from Maillard reaction.

Flip the fillets and cook the second side 1–2 minutes until just cooked through — internal temperature should reach 53–55°C (127–131°F) for moist cod. Fish continues to cook from residual heat; removing it slightly early preserves a tender texture.

Make the lemon-caper pan sauce: remove the fish to a warm plate and lower the heat to medium. Add the butter to the skillet; when it begins to foam, add the rinsed capers and 1 tablespoon lemon juice and scrape up the fond (browned bits) with a wooden spoon. The butter dilutes and enriches the pan juices while capers give briny contrast; deglazing incorporates concentrated flavor into the sauce.

Swirl the butter, taste and adjust seasoning, then remove pan from heat. Spoon the warm lemon-caper butter over the cod. The quick finishing sauce glosses the fish and ties together the citrus and brine notes.

Plate: mound the herbed couscous in the center of warm plates, set a cod fillet on top, drizzle with extra caper-butter sauce, scatter the pea shoots or microgreens, and finish with a few turns of freshly ground black pepper and an extra pinch of herb and lemon zest for brightness. Serving immediately keeps textures crisp and flavors lively.