In a medium saucepan, add the onion, garlic and spices. Cook over low-medium heat until fragrant and the onions become translucent, about 4-5 minutes.
Add the water, zest and orange juice and bring to the boil. Reduce heat and continue cooking for a few minutes so the flavors can build.
Add the shrimp, stir and cover. Turn off the heat and let the shrimp rest for about 10 minutes.
Remove the shrimp and transfer to the fridge until completely cool, at least 2 hours.
Mango Avocado Salsa
Chop the mango into large chunks, and process it on pulse in a small food processor until it's broken down into tiny little pieces, just before it becomes a puree.
Transfer to a small mixing bowl.
Add the rest of the ingredients and mix well.
Assembly
Divide the salsa between 2 cocktail glasses and place 5 shrimps around the rim (you can shell the shrimp or not, your decision)