First, make the ratatouille

Preheat oven to 400°F.

In a medium ovenproof skillet,sauté onion in 1 tablespoon olive oil until soft and starting to caramelize, about 15 minutes.

Add the paste or anchovies and cook until melted into the onion.

Meanwhile in a small bowl, combine 3 tablespoons olive oil, the tomato paste, garlic, herbs, chili flakes, salt and pepper. Whisk and taste for seasoning. The mixture should be well seasoned as it will flavor all the vegetables.

In a large mixing bowl, combine the caramelized onions, zucchini, eggplant and tomatoes. Add the sauce to the vegetables and toss until evenly coated.

Transfer the vegetables back to the skillet and cook until the vegetables are hot and just starting to cook. Transfer to oven and roast for 45–60 minutes, stirring the vegetables once halfway through. The vegetables should be browned, and the sauce dark and rich. Stir in a handful of basil and oregano. Season to taste with salt and pepper. Keep warm in the oven.

In a nonstick skillet, heat the remaining 1 tablespoon olive oil. Salt and pepper the fish fillets. Cook on one side until golden in color, 3-5 minutes. Flip and cook for about 3 minutes on the second side, until just cooked through.

Serve fish over top of ratatouille.