Grilled Pompano With Smoked Tomato And Balsamic Vinaigrette

• 12 year old balsomic vinegar
• 4 tomatoes
• 2 on both sides of the pompano (inches apart)
• 1 salt pepper
• 1/2 bunch onion (minced)
• 1/2 deep slits
• 600 gr pompano (cleaned)
• 2 gr basil chiffonade