Preheat oven to 450 degrees.
Cut 8 (12-inch) squares of heavy-duty foil. Pat salmon dry and season with salt and pepper.
Place 1 piece of salmon on 1 piece of cut foil.
Top each with diced mango, carrots and snow peas.
Pour 1 tablespoon soy sauce on top of salmon and veggies, top with 1 piece of butter.
Place second piece of foil over salmon and veggies.
Fold foil pieces together, around all four sides, creating approximately a 7-inch square.
Place on rimmed baking sheet and bake for 15 to 20 minutes, depending on desired doneness of salmon.
Note: Your favorite firm white fish such as tilapia can be substituted for salmon. Just purchase same size fillets and follow recipe as follows.