Spanish-style grilled fish

Ingredients:

• 4 large red onions, cut into thin rings
• 3/4 cup olive oil
• 1/2 cup red wine vinegar
• 1 head of garlic, separated into cloves and peeled
• 1 lemon, cut into thin slices
• 1 bunch green onions, cut into rings
• 2.5 tbsp paprika
• 2 tsp ground cayenne pepper
• 2 - 3 branches rosemary
• 2-3 sprigs of thyme
• Coarse salt
• 1 whole fish weighing 1.3 - 2.7 kg (sea bass, striped bass or sea bass), cleaned and gutted
• Vegetable oil, for grilling

Preparation:

1. Preheat the grill to medium-high heat. In a large bowl, combine 1 sliced ​​onion, 1/2 cup olive oil, vinegar, garlic, lemon slices, green onions, 1 1/2 tablespoons paprika, cayenne pepper, rosemary, thyme, and 2 teaspoons salt. Let the mixture marinate at room temperature for 1 hour.
2. Place the remaining 3 sliced ​​onions in an even layer in a baking dish. Brush with 2 tablespoons olive oil and sprinkle with 1/2 tablespoon paprika and 1 teaspoon salt.
3. In a bowl, combine the remaining 2 tablespoons of olive oil with 1/2 tablespoon of paprika. Rinse the fish under water, pat dry, and rub with the oil and paprika mixture. Fill the fish cavity with the marinated mixture. Transfer the remaining filling to the onion-lined dish.
4. Brush the grill grate with vegetable oil. Sprinkle the fish with 1/2 teaspoon of salt on one side; place it on the grill, salted side down, and grill for 4 to 5 minutes. Sprinkle the other side with 1/2 teaspoon of salt; carefully flip it over and continue grilling for another 4 to 5 minutes.
5. Transfer the fish to a baking sheet and let it rest, uncovered, for 10 minutes. Meanwhile, place the baking dish with the onions on the grill. Cover and cook, stirring occasionally, until the onions begin to soften, 8 to 10 minutes.
6. Remove the pan with the onions and reduce the grill temperature to medium (if using a charcoal grill, move the coals apart). Place the fish on top of the onions. Pour 3/4 cup of water into the pan; place on the grill, cover, and continue cooking for another 20-25 minutes.
7. Place fried onions and filling on a plate and place the fish on top.