Cut trout in half lengthwise.
Place skin side up on foil-lined broiling pan.
Sprinkle with 2 tablespoons lemon juice.
Broil 4 inches from source of heat for 3 minutes.
Turn trout over and sprinkle with remaining lemon juice; broil 3 to 5 minutes till fish flakes easily at the touch of a fork.
Dot trout with margarine and broil 1 minute longer.
Garnish with parsley and lemon wedges.