Preheat oven to 400 degrees.
Line a baking pan with aluminum foil wrap. Cut salmon into about six pieces, each about 3- × 3-inch and place in the prepared pan.
Cover each piece of salmon with a layer of mayonnaise then cover the mayonnaise with a layer of ketchup.
Sprinkle minced onion over each serving then evenly divide turkey bacon pieces (if using) over the fish.
Bake for 20 to 25 minutes.