Preheat the grill or grill pan to medium-high heat, approximately 400°F (200°C).
Pat salmon fillets dry with paper towels and brush with 2 tablespoons of olive oil.
Season both sides of the fillets with salt and black pepper.
Place salmon on the grill grates. Grill for 4 to 5 minutes per side until the internal temperature reaches 145°F (63°C).
In a medium mixing bowl, combine diced avocados, minced red onion, chopped cilantro, lime juice, extra-virgin olive oil, and minced garlic.
Gently toss the salsa ingredients to combine, ensuring the avocado cubes remain intact.
Remove the salmon from the heat and allow it to rest for 2 to 3 minutes.
Serve each salmon fillet topped with a portion of the avocado salsa.