In a medium bowl, combine the salmon fillets with oregano, minced garlic, olive oil, and fresh lemon juice. Season with kosher salt and cracked black pepper. Mix well and set aside.

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

Carefully place the marinade-coated salmon fillets skin-side down in the hot skillet. Cook for approximately 5 minutes, until a golden-brown crust forms.

Gently flip the salmon fillets using a fish spatula and reduce the heat slightly to medium. Cook for another 2-3 minutes, until the fish flakes easily.

In a separate bowl, mix cherry tomatoes, olives, diced cucumber, chopped parsley, and basil. Drizzle with olive oil and season with salt and pepper. Toss to combine.

Transfer the cooked salmon to a serving platter and top with the vegetable mixture. Serve immediately.