2. Fill a large saucepan with enough water to cover fish. Bring to a boil over high heat. Reduce heat to low and place salmon in pan. Make sure salmon is completely covered with water. Cover and simmer on low for 18 minutes only.
3. Remove from heat. Remove salmon from water and place in a non-reactive dish (do not use foil).
Prepare the Sauce
1. To prepare sauce, combine duck sauce, ketchup, brown sugar, lemon juice, vinegar, and thinly sliced red onions. Pour over salmon and marinate overnight. Keep refrigerated.
To serve, scoop a generous amount of sauce over salmon.