How to Make It
Combine 2 tablespoons of the olive oil with the lemon juice and salt. Stir to dissolve the salt.
Heat a large nonstick skillet over high heat. When the pan is hot, dip half of the monkfish in the oil marinade. Place the medallions in the skillet without touching and sear, turning once, until golden brown, about 2 minutes per side. Transfer the fish to a warm platter. Repeat with the remaining medallions.
Wipe out the skillet. Add the remaining 6 tablespoons oil and warm over moderate heat. Add the garlic and cook until golden, about 2 minutes. Stir in the red pepper and vinegar.
Pour the sauce over the fish and sprinkle the parsley on top.