Preheat oven to 400°F and line a baking sheet with parchment paper.
Pat fish dry with paper towels. Score the skin of each fish with 3 shallow diagonal cuts on both sides. Season generously with salt and pepper inside the cavity and over the exterior.
Rub one side of each baguette slice with olive oil, then toast under the broiler for about 2 minutes until golden. Set aside.
In a small bowl, combine minced garlic, remaining olive oil, chopped basil, parsley, capers, and red wine vinegar.
Place fish on prepared baking sheet, flesh side up. Arrange lemon slices over top of each fish. Roast for about 12-15 minutes until the internal temperature reaches 140°F at the thickest part — it should be just opaque and flake easily with a fork.
While fish cooks, spoon herb mixture evenly onto toasted baguette slices.
Carefully lift cooked fish from baking sheet (leaving behind any lemon juice that dripped off), then use a spatula to gently separate the flesh along the backbone. Remove bones and arrange fish meat over the bruschetta base.
Serve immediately while still warm, garnished with extra lemon slices if desired.
