Cut fillets into cubes (1/4 to 1/2 inch). Place in deep bowl and cover completely with fresh squeezed lime juice. Add diced onion, bell pepper, hot peppers if desired, garlic (coarse powdered or fresh), chopped fresh cilantro, and whatever other seasoning you like. Cover and let stand in refrigerator several hours or until fish is tender and white. Add diced tomatoes and avocado (optional). Add Italian dressing to cover other ingredients. Can be enjoyed immediately, with your favorite crackers or tortilla chips. Or left to sit a little longer for even more flavor.