Heat A Grill To Medium-High Heat Or Have A Ridged Grill Pan Ready. Cut 1 Of The Oranges In Half And Squeeze 2 Tablespoons Juice. In A Medium Bowl, Combine Olive Oil And Juice. Spoon 2 Tablespoons Of The Mixture Over Fish. Sprinkle Paprika Over Fish; Let Stand 10 Minutes. Peel Remaining Orange And Separate Into Sections. Add The Orange Sections And Fennel To The Bowl; Toss With Olive Oil Mixture. Grill Fish (Or Cook In A Heated Ridged Grill Pan Over Medium Heat) 4 Minutes Per Side Or Until Fish Is Opaque In Center. Transfer To Serving Plates And Top With Fennel And Orange Mixture And Sea Salt. Garnish With Tarragon If Desired.