Mix the salt, chili powder, cumin, paprika, onion and black pepper together, rub the salmon fillets with olive oil and this seasoning mix
Refrigerate for at least 30 minutes
Pre-heat the grill
Combine the avocado, onion, cilantro, and lime juice in a bowl and mix well, chill until ready to use
Grill the salmon to desired doneness (I grilled for about 5 minutes)
Top with avocado salsa and enjoy!