Preheat the oven broiler.
In a saucepan stir together the vinegar, beer, honey, garlic, ginger, chili flakes, soy sauce, and cornstarch. Add the pan to a burner over high heat, boiling until thickened, about 5 minutes.
Cover a sheet pan with aluminum foil, drizzle with olive oil, add the salmon, skin side down. Sprinkle the salmon liberally with salt.
Brush the salmon with the sauce.
Place about 4-6 inches under the broiler, keeping a close eye.
After 5 minutes, remove from oven and re-brush with the sauce. Return to the broiler until starting to brown.
Plate the salmon, sprinkle with sesame seeds and cilantro.