Combine lime zest, lime juice, vinegar, water, mint, sugar, and salt in a small saucepan. Bring to a simmer for five minutes. Remove the mint leaves.

Add chopped celery and tomatoes to a small heatproof bowl. Pour hot pickling liquid over the vegetables. Let the vegetables sit in the liquid for ten minutes.

Preheat the broiler of the oven to high.

In a small bowl, mix together the olive oil, salt, pepper, and zest. Place fish filets on baking sheet. Rub the olive oil mixture over each side of the fish.

Place fish under the broiler, leaving the door slightly ajar, for 5-7 minutes until cooked through and flaky.

After the ten minutes or so of soaking, drain the liquid from the tomatoes and celery. Add herbs and green onion to the celery and tomatoes. Mix well.

Serve fish with a spoonful or two of the relish on top. Relish would also be a nice topping on any other kind of protein.