Measure and prep everything before you heat anything. Rinse the trout and pat each fillet very dry (you want dry skin so it crisps). Zest then juice the lemons into a small bowl and combine with half the chopped dill (2 tbsp), 2 tbsp olive oil, a pinch of salt and pepper — this is your finishing vinaigrette. Prepping ahead means the grill/stovetop work is quick and precise; dry fish gives the best sear.

Toast the couscous: heat 1 tbsp olive oil in a medium saucepan over medium heat, add the dry Israeli couscous and toast, stirring, until the pearls are fragrant and beginning to turn golden (about 3–4 minutes). Toasting blooms the nutty flavors and keeps the pearls from going gluey.

Add 2 1/2 cups of simmering water or low‑sodium stock (use 1:2.5 couscous:liquid by cups), a pinch of salt, reduce heat to low, cover and simmer gently until the pearls are tender but still separate (about 8–10 minutes). Turn off the heat and let sit, covered, 5 minutes — resting lets any remaining steam finish the cooking without overcooking.

While the couscous cooks, quick‑pickle the fennel: put the thin fennel slices in a bowl, add 4 tsp sherry or red wine vinegar, a pinch of salt, and 1 tsp of lemon juice. Toss and let sit 8–10 minutes. Quick‑pickling softens fennel’s raw sharpness and brightens the flavor for contrast against the rich trout.

Toast the walnuts: in a small dry skillet over medium heat, toast the roughly chopped walnuts, stirring frequently until fragrant and slightly darker (2–3 minutes). Watch carefully — nuts burn fast. Remove to a plate to stop carryover cooking.

Char the fennel: heat a cast‑iron grill pan or outdoor grill to medium‑high and brush fennel slices lightly with oil and sprinkle with salt. Place fennel on the hot surface and cook 2–3 minutes per side until you have good char marks and some softening. Charring adds smoky sweetness that plays against the quick‑pickled brightness.

Wilt the kale: in a large sauté pan, heat 1 tbsp olive oil over medium, add the minced garlic and thyme and cook 20–30 seconds to bloom the aromatics (don’t let the garlic brown). Add the shredded kale, a pinch of salt and 1–2 tbsp water, and cook, tossing, until the kale is wilted but still bright green (3–4 minutes). Finishing with a splash of lemon juice keeps the greens vibrant and adds acidity to balance the dish.

Finish the couscous: fluff the rested couscous with a fork, fold in the wilted kale, most of the chopped toasted walnuts (reserve a tablespoon for garnish), the remaining dill, lemon zest, and a tablespoon of olive oil. Taste and season with salt and pepper. Tossing in the warm kale distributes its juices and melds the flavors — don’t skip the zest; it brightens the whole dish.

Season and oil the trout: brush each fillet on both sides with a thin coat of olive oil and season generously with salt and pepper. Let sit at room temp while your pan is getting hot (this promotes even cooking).

Grill the trout, skin‑side down: preheat a grill or a heavy skillet to medium‑high and add a thin film of oil. Place the trout skin‑side down and press gently with a spatula for 15–20 seconds to prevent curling. Cook without moving until the skin is deeply golden and crisp (about 4–5 minutes depending on heat and fillet thickness). Cooking skin‑side down first renders the fat and gives a crisp texture that contrasts the tender flesh.

Flip briefly: flip the fillets and cook the flesh side for just 1–2 minutes until the trout reaches about 120–125°F (49–52°C) for medium; it will continue to carry over‑cook while resting. Steelhead is resilient and oily — a quick flip keeps the fillet moist and flaky.

Rest and finish: remove the trout to a cutting board and rest 3 minutes. Spoon the lemon‑dill vinaigrette over the fillets so the citrus brightens the fish without cooking it further. Resting lets juices redistribute and keeps the fish tender.

Plate: spoon a bed of the warm couscous and wilted kale in the center of each plate, arrange charred fennel slices on top, and crown with the grilled trout. Scatter the remaining toasted walnuts and a little extra chopped dill, and finish with a grind of black pepper and a light sprinkle of sea salt. Serve immediately.