Make Seasoning: In a small bowl, add 1 tablespoon paprika, 2 teaspoons onion powder, 2 teaspoons garlic powder, ½ teaspoon cayenne pepper, 1 teaspoon dried oregano, 1 teaspoon kosher salt, ½ teaspoon ground black pepper, ½ teaspoon cayenne pepper, and ¼ teaspoon chipotle pepper. Mix to combine.
Season Salmon: Pat 4 salmon fillets dry with clean paper towel. Rub salmon all over with blackened seasoning. Drizzle 1-2 tablespoons of olive oil over seasoned salmon; rub into salmon.
Cook Salmon: Bring a large cast iron skillet to medium-high heat. Add 1 tablespoon of oil; swirl to coat the pan. Sear salmon (skin-side up) for approx. 1-3 minutes (or until there is a good char). Flip salmon over so skin side is down and place in the oven (middle rack and uncovered). Let cook 10-14 minutes or until fully cooked (internal temperature of 145℉). Remove from oven and let cool slightly.
Build Salads: Divide 4-6 cups romaine lettuce between 4 bowls. Place one piece of salmon in each bowl. Add parmesan cheese, avocado, hard-boiled egg and pickled onions (if desired).