In a shallow dish, whisk together the paprika, thyme, oregano, onion powder, garlic powder, kosher salt and cayenne.
Sprinkle the halibut fillets with the seasoning mixture, pressing with your fingers to help the coating adhere.
Heat a large nonstick skillet over medium-high heat, 2-3 minutes. Traditionally you would use a cast iron skillet, but I use a nonstick hard anodized aluminum skillet to minimize the risk of sticking.
Add the butter to the hot skillet and swirl to coat. Add the halibut fillets. Cook 4 minutes on each side, until the fillets turn from translucent into opaque and white (it’s fine to cut a small slit and peek).
Spoon the pan juices on top of the fish, and serve.