1. Preheat grill to medium-high or 400F (205C). Position rack 3 inches above heat. Rinse trout and pat dry. Combine pecans, olive oil, garlic, green chile and cilantro, if using, in a small bowl. Cut lime in half crosswise and squeeze juice over pecan mixture. Slice remaining lime half into 4 rounds and set aside. Stuff cavity of each fish with pecan mixture, securing stuffing with wooden picks or small metal skewers
2. Using vegetable oil, lightly oil fish and place on grill rack. Grill about 6 minutes or until trout becomes lightly browned. Turn gently, keeping trout whole, and grill other side about 5 minutes or until fish begins to flake. Garnish with thin lime slices, cut in half and twisted.
Pecans can be toasted in a heavy skillet on the grill or indoors over medium heat for about 5 minutes, stirring occasionally.