juice over the tomato and salmon.
fold the sides of the foil over the fish, tomato and onion mixture, covering completely; seal the packets closed. place the foil packet on a large and heavy baking sheet.
repeat until all of the salmon have been individually wrapped in foil and placed on the baking sheet.
bake until the salmon is just cooked through, about 20-25 minutes (you may also cook it outside on the grill).
using a large metal spatula, transfer the foil packets to plates. serve with jasmine rice and steamed broccoli. 