This healthy grilled fish dish is made for easy summertime entertaining. The peperonata can be made in advance and reheated while you grill the fish.
Heat 2 tablespoons oil in a large pot over medium-low heat. Add garlic, fennel seed and crushed red pepper and cook, stirring often, until fragrant and the garlic starts to brown, 2 to 3 minutes. Add onion and cook, stirring occasionally, until softened, about 5 minutes. Stir in oregano, thyme and paprika. Add bell peppers, reduce heat to low and cook, stirring occasionally, until softened, about 20 minutes. Add capers and vinegar and cook for 2 minutes more.
Meanwhile, preheat grill to medium-high.
Brush fish with the remaining 2 tablespoons oil and sprinkle with salt. Oil the grill rack. Grill the fish, turning once halfway, until the flesh is opaque, 6 to 10 minutes total, depending on thickness. Transfer the fish to a clean cutting board and cut into 4 portions.
Arrange the fish over the peperonata and top with herbs and fennel.
To make ahead: Refrigerate peperonata (Step 1) for up to 1 day.
4 1/2 lean protein, 3 fat, 1 1/2 vegetable