Roasted Black Sea Bass with Tomato and Olive Salad

Ingredients

• 0.5 teaspoon anchovy paste 
• 0.5 pound cherry tomatoes mixed quartered (preferably colors)
• 1  garlic clove 
• 0.5 pound grape tomatoes mixed halved (preferably colors)
• 12  kalamata olives pitted coarsely chopped
• 2 tablespoons olive oil extra-virgin divided
• 1.5 tablespoons oregano chopped
• 6 sprigs oregano (3-to 4-inch)
• 0.5 medium onion red thinly sliced
• 2 tablespoons red-wine vinegar 
• 24 ounce sea bass fillets black with skin, any pin bones removed
• 4  sun-dried tomatoes packed in oil, chopped

Equipment

• bowl
• oven
• knife
• whisk
• baking pan
• kitchen twine

Directions

1. Mince and mash garlic to a paste with 1/2 teaspoon salt.
2. Transfer to a bowl and whisk in anchovy paste, vinegar, and 1/4 teaspoon pepper.
3. Whisk in oil. Toss with remaining salad ingredients.
4. Let stand, stirring occasionally, while fish roasts.
5. Preheat oven to 425°F with rack in middle. Oil a 1 1/2-to 2-quart gratin or other shallow baking dish.
6. Rub flesh sides of fish with 2 teaspoons oil (total) and season with 3/4 teaspoon salt and 1/4 teaspoon pepper (total). Divide onion slices and oregano sprigs into 2 portions and sandwich each portion between 2 fillets, skin sides out. Tie with kitchen string crosswise at 2-inch intervals and transfer to baking dish. Score skin on top in several places with a sharp knife and drizzle with remaining 4 teaspoons oil.
7. Roast fish until just cooked through, about 15 minutes.
8. Cut off string and cut sandwiched fillets in half crosswise.
9. Serve topped with salad.
10. Salad can be made 6 hours ahead and kept at room temperature.