01 -
In a mixing bowl, combine softened butter, chopped rosemary, lime juice, lime zest, and chili flakes. Mash thoroughly until all ingredients are evenly incorporated.
02 -
Transfer the butter mixture onto a large piece of plastic wrap. Shape into a log, roll tightly, and refrigerate until firm, at least 1 hour.
03 -
Heat an outdoor grill to medium-high heat (about 200°C). Clean and lightly oil the grates to prevent sticking.
04 -
Pat fish fillets dry with paper towels. Brush both sides with olive oil, then season evenly with garlic powder, sea salt, and black pepper.
05 -
Place the fillets skin-side down on the grill. Cook undisturbed for 8–10 minutes, allowing the skin to char and crisp.
06 -
Flip fillets carefully and grill for an additional 2–4 minutes, or until just cooked through and opaque in the thickest part.
07 -
Transfer grilled trout to serving plates. Top immediately with slices of the chilled compound butter. Garnish with fresh lime slices and chopped parsley if desired.