Place goji berries in a small bowl with a bit of water for just a few minutes until they plum up.
Remove the avocado pits and scoop each avocado into a medium bowl. Add generous squeezes of lime and plenty of sea salt. Lightly mash the avocado with the back of a fork.
Stir in chopped mango, goji berries, red onion, jalapeño and cilantro. Add salt and pepper (and more lime if necessary), to taste. Serve immediately.