Heat a grill pan or outdoor grill over medium-high heat.

Drizzle half of the oil over the fish and season with salt.

Grill fish 4 minutes on each side until fish is firm but not tough and cooked through.

Preheat a safe, non-stick skillet over medium-high heat.

While fish cooks, peel the orange, cut off ends and slice into rounds, then in quarters.

Add remaining oil, fennel and onions to the preheated skillet.

Cook 3 to 5 minutes until seared and beginning to soften. Add vinegar and swirl. Remove from heat.

Add in the oranges, the parsley and oregano.

Place fish on serving plates, topped with fennel-orange salad.

Serve.