Place the fish steaks in a shallow baking pan and set aside.
In a medium bowl, whisk together olive oil, lemon juice, minced garlic, paprika, cumin, cayenne, salt, and black pepper until completely emulsified. Stir in parsley and cilantro. Set aside ½ cup marinade.
Pour the remaining marinade over the fish in the baking pan, and refrigerate for at least 3 hours, or overnight. Turn fish over in pan halfway through marinating.
Prepare the grill.
Grill the fish until the flesh flakes easily, approximately 10 minutes per inch of thickness. Spoon the reserved marinade over the cooked fish, and serve immediately.