Smoked Swordfish Salad Mazatlan

Name: Smoked Swordfish Salad Mazatlan
Ingredients: 3/4 pound swordfish, in one piece; 1/3 cup cider vinegar; 1 large clove garlic, minced; 1/2 teaspoon salt; 1/2 tablespoon freshly ground black pepper; 1/2 teaspoon sugar; 1/2 avocado, peeled; 2/3 cup olive oil; 3 green onions, white and light green parts only, finely chopped; 1 small white onion, sliced paper thin and, if desired, soaked in ice water for 2 hours; 3 cups spinach leaves, well washed; 1 head butter lettuce, outer leaves discarded and inner leaves torn into bitesized pieces; 1 pint cherry tomatoes, halved