In a large bowl, cut and prepare: shrimp, onion, garlic, tomatoes, jalapeno, Serrano, cilantro, mango. Once you have done that, stir together lightly.
Squeeze the orange, lemon, and lime juices in to the shrimp mixture, add the avocado last to prevent it from turning brown. Drizzle the olive oil. Toss with the cumin and salt and pepper to taste.
This can be served in a cocktail glass garnished with a slice of lime along with a sprig of cilantro and eaten with a salad fork or in a bowl with tortilla chips on the side. Yummy!