Preheat the broiler. Line a baking sheet with aluminum foil. In a small bowl, combine the honey and soy sauce and mix well. Lay the salmon, skin side down, on the baking sheet. Drizzle a quarter of the sauce over the salmon. Sprinkle with the red pepper flakes and fennel and broil 2 inches from the heat source for 10 to 15 minutes, depending on the thickness of the salmon. Drizzle every 2 to 3 minutes with the remaining sauce until the salmon turns a deep mahogany, is opaque and flakes when pierced with a fork. Do not allow it to char. Serve immediately.