Rosemary, lemon, and capers are a marriage made in heaven for white fish. This recipe is simple, and makes any white fish taste special, without too much cooking. For a real southern Mediterranean... feel, try scattering anchovies onto the dish before baking.
Mix the garlic, rosemary, capers, lemon zest, and olive oil in a bowl. Roll the fish in the oil and herbs. Leave to sit in the fridge for 10-15 minutes.
While the fish is marinating, preheat the oven to 425 degrees.
Put the fish in a shallow baking dish in a single layer. Cover with the remaining marinade. Season with salt and pepper. Layer the lemon slices over the fish, overlapping them to look like scales. Pour lemon-water mixture around the fish.
Bake on a high shelf for 15-20 minutes or until the fish is just done. The lemon slices will be golden and caramelized.
Take the fish out of the oven and let it sit for about 5 minutes to steam and finish cooking. Serve immediately.