Whisk together olive oil, oregano, minced garlic, and lemon juice in a medium bowl. Coat the salmon fillets with the marinade and season with kosher salt and cracked black pepper. Let marinate for 5 minutes.

Heat a large cast-iron skillet over medium-high heat and add a drizzle of olive oil until it shimmers.

Place marinated salmon fillets skin-side down in the skillet and cook for approximately 5 minutes without moving them until the skin is crispy and golden brown.

Gently flip the salmon fillets and cook for an additional 2-3 minutes until opaque and flakes easily with a fork.

Combine cherry tomatoes, olives, cucumber, parsley, basil, and feta cheese in a bowl. Toss with a sprinkle of salt and pepper.

Spoon the veggie topping over the plated salmon fillets and serve immediately.