01 - Preheat the oven to 400°F (200°C). Line a baking sheet with parchment paper or lightly grease it with olive oil.
02 - Pat the halibut fillets dry. Place them on the prepared baking sheet.
03 - Drizzle halibut with olive oil, lemon juice, and lemon zest. Season with salt and pepper.
04 - Bake for 15–18 minutes, or until the fish is opaque and flakes easily with a fork.
05 - Meanwhile, prepare the tomato basil relish: In a medium bowl, combine cherry tomatoes, basil, shallot, capers (if using), olive oil, balsamic vinegar, salt, and pepper. Toss gently to mix.
06 - Remove halibut from the oven and let rest for 2 minutes.
07 - Plate the halibut fillets and generously spoon the tomato basil relish over the top.
08 - Serve immediately with lemon wedges, if desired.