Pat the salmon fillets dry with paper towels. Season both sides generously with salt, pepper, dried oregano or a garlic/herb seasoning blend.

In a large skillet, heat 1 tablespoon of olive oil over medium heat. Add the string beans and cook, stirring occasionally, for about 5-7 minutes until they are tender-crisp. Add the minced garlic and cook for another minute. Transfer the beans to a plate and keep warm.

In the same or another large skillet, add the remaining olive oil and butter. Once the butter has melted and the oil is hot, place the salmon fillets skin-side down in the pan. Cook for 4-5 minutes on the skin side until it is crispy and golden brown. Flip the fillets and cook for another 2-3 minutes, or until the salmon is cooked through.

Arrange the string beans and mandarin segments on a serving platter. Place the salmon fillets on top and garnish with lemon wedges if desired.