1 Defrost frozen shrimp: If you are starting with frozen shrimp, put a quart of cold water in a large bowl and add a tablespoon of salt. Stir until the salt is dissolved. Add the shrimp and several large ice cubes. Let sit until defrosted (keep ice in the water).
If your shrimp is fresh or already defrosted, if you want you can put the shrimp in salty water for 15 minutes or until you are ready to thread skewers and grill the shrimp.
2 Prepare the salsa: Place the chopped mango, avocado, red onion, jalapeño in a bowl. Sprinkle with salt and gently toss with fresh lime or lemon juice. Add fresh cilantro (if using) right before serving.
3 Prepare your grill for high direct heat (you’ll know it’s hot enough when you can hold your hand 1 inch above the grill grates for 1 second).
4 Thread the shrimp onto skewers: Use two bamboo skewers at a time to thread the shrimp. This will make it easier to turn and keep the shrimp from spinning on the skewer.
Starting at the big end of the shrimp, hold the shrimp in a tight spiral like the shape of an apostrophe. Starting at the large end of the shrimp, thread the 2 skewers through the shrimp, starting at the big end and going through the smaller end, right before the tail section.
Thread 3 to 4 or more on a skewer, depending on how long your skewers are, leaving a little space between each shrimp so that the shrimp cook evenly.
Brush shrimp with a thin coating of olive oil on both sides.
5 Grill the shrimp: Brush hot grill with a wadded up paper towel soaked in olive oil. Place the skewers of shrimp on the hot grill. Grill for 2-5 minutes per side, depending on how hot your grill is and how big your shrimp are.
The cut end of the shrimp will change from translucent to opaque as it cooks. It’s done when it is just barely opaque. Take it off the grill. Don’t overcook or your shrimp will be rubbery!
Remove the shrimp from the skewers when they are still relatively hot (they’ll slide off better when warm).
6 Warm the tortillas: Depending on the type of tortilla you are using (flour tortillas work well, as do soft white corn tortillas), you can put them on the grill for a few moments to toast them just a little on each side.
You can also warm tortillas in a microwave (works well to soften them), or in a frying pan. If warming corn tortillas in a frying pan, it helps to add a little oil to the pan.
To serve, place a few shrimp in the center of a tortilla and top with mango avocado salsa!