Pre-heat oven to 400 degrees F.
Place the salmon filets on to pieces of tinfoil on a baking tray. Make sure the tinfoil is big enough to be able to wrap the salmon into a little pouch.
Season the salmon with some salt.
Add 2 small pats of butter to each filet and then place thing lemon slices over the butter.
Wrap up the tinfoil around the fish to create a little pouch. Bake in the oven for 11-13 minutes. Salmon is done when it flakes easily with a fork in the thickest part.
While the salmon bakes, make the mango salsa:
Dice the mango, red pepper, red onion, jalapeno and cilantro.
Toss all the ingredients in a bowl to combine.
Top with the juice from 1 lime and the salt.
Stir and keep in the fridge until the salmon is ready.
Divide salmon and mango between plates. Serve with rice (if desired).