Preheat oven to 375 degrees F.
Juice half the lemon. Cut the remaining half into 4-5 lemon slices.
In a small skillet, add butter, garlic, red pepper flakes, salt and pepper, and sauté, stirring frequently, to melt the butter. (This could be done in the microwave if you want.) Remove skillet from heat. Stir in reserved lemon juice.
Next, oil a large sheet pan. Place trout filet on pan. Add veggies to the pan.
Pour butter mixture over fish and vegetables. Use a pastry brush to rub the butter mixture into the fish. Place lemon slices across the trout and bake for about 15 minutes until cooked through.
Top cooked trout with chopped parsley. Serve immediately.
