Bring a medium salted pot of water to a boil. Add the shrimp in and cook for 3-4 minutes or until they turn pink and are cooked through, taking care not to overcook. Prepare a bowl filled with ice water and ice cubes to cool the shrimp when they're done. 

Scoop out most of the avocado flesh into a medium bowl. Mash in the lime juice, cilantro, chives, and paprika.

Once the shrimp are done, immediately drain them then dunk them into the ice bath. Let them cool for a couple of minutes and then drain and dry them (with a piece of paper towel). 

Roughly chop the shrimp and add them in with the avocado mixture. Season with salt & pepper as needed (I found I needed a fair bit of salt in this recipe). Divide the mixture between the 4 avocado halves. Serve immediately.