A drizzle of sweet Guava Vinaigrette is what makes this Cuban avocado salad sing.
Using a soupspoon, scoop out avocado flesh in one piece; reserve shell. Cut flesh into 1/2-inch dice; set aside. Repeat. Separate orange sections; discard membranes.
Place oranges, cucumbers, three-fourths of tomatoes, cilantro, onions, and vinaigrette in a bowl; toss. Add avocado; gently toss. Divide among shells. Garnish with cilantro, remaining tomatoes, and any extra salad.