Halve the cherry tomatoes (or dice plum tomatoes) into roughly uniform pieces so they release some juice but still hold shape. Finely mince the shallot and chiffonade or thinly slice basil if using. Chop the parsley.

Combine and season

In a medium bowl, combine the tomatoes, minced shallot, rinsed capers, chopped parsley and basil. Add the extra-virgin olive oil, lemon juice, red wine vinegar, and lemon zest. Season with 1/2 tsp salt and 1/4 tsp freshly ground black pepper. Stir gently to combine.

Rest to marry flavors

Let the relish sit at room temperature for 10–15 minutes (or refrigerate up to 1 hour) to let flavors meld. Taste and adjust seasoning with more salt, lemon juice or olive oil if needed before serving.

Fish

Dry and season the filets

Pat the red mullet filets thoroughly dry with paper towels, especially the skin side — dry skin sears better. Season both sides lightly with 1 tsp fine sea salt and 1/2 tsp freshly ground black pepper, distributing seasoning evenly across the 4 filets.

Heat pan and oil

Place a large nonstick or well-seasoned stainless-steel skillet over medium-high heat. Add 2 tbs olive oil and heat until shimmering but not smoking (about 1–2 minutes). To test, tilt the pan and the oil should flow easily.

Pan-sear skin-side down

Carefully place each filet skin-side down in a single layer, pressing gently for 10–15 seconds with a spatula to keep the skin flat. Cook undisturbed for 2.5–3.5 minutes, until the skin is deeply golden and crisp and the flesh has changed color about two-thirds of the way up.

Finish on flesh side

Flip the filets gently and cook on the flesh side for 30–60 seconds (depending on thickness) until just cooked through — fish should flake easily but remain moist. Total cook time per side will vary; aim for an internal temperature around 54–56°C (130–133°F) for medium; a little more for well-done.

Rest briefly

Transfer the cooked filets to a warm plate and let rest 1–2 minutes while you finish the relish if needed. Spoon any pan juices over the filets.

To Serve

Assemble and plate

Divide microgreens or baby arugula among four plates if using. Place one warm red mullet filet on each bed (skin-side up). Spoon 2–3 tablespoons of the tomato and caper relish over the flesh of each filet, leaving the skin visible and crisp.

Garnish and finish

Finish each plate with a sprinkle of chopped parsley, a grind of black pepper, and a lemon wedge alongside. Serve immediately so the skin remains crisp.