Saute the red onion in the olive oil until lightly caramelized. Add the passion fruit puree, casacabel chile puree, and mango puree to the onions. Reduce the mixture for 2 minutes and add the sherry vinegar. Chill the sauce and set aside. Add the finely sliced scallions to the chilled mixture and mix well. Season and serve warm.
Recipe courtesy of Herve Cuyeu, Loews Miami Beach Hotel, Florida