Preheat your oven to 375°F (190°C).
Prepare a baking sheet by lining it with parchment paper or lightly greasing it.
In a bowl, mix olive oil, lemon juice, lemon zest, minced garlic, salt, and pepper.
Place the salmon fillets on the prepared baking sheet, skin side down.
Spoon the olive oil mixture over each salmon fillet, making sure to coat them evenly.
Top each fillet with crumbled feta cheese and sliced avocado.
Bake in the preheated oven for about 15-20 minutes, or until the salmon flakes easily with a fork.
Once baked, garnish with fresh herbs before serving.