1Place haddock pieces, thickest parts to outside edge, in 24-ounce shallow microwavable casserole. Sprinkle with salt and pepper. Place onion and tomato on haddock. Sprinkle with lime juice and oil. Top with olives.
2Cover loosely and microwave on High 4 to 5 minutes or until fish flakes easily with fork. Serve with avocado and lime.