Rinse the raw shrimp under cold water, ensuring they are peeled and deveined.

In a medium pot, bring water to a boil. Add half the lemon juice, garlic cloves, and salt, and let simmer.

Add the shrimp to the simmering water and cook until they turn pink and opaque (about 2-3 minutes).

Use a slotted spoon to transfer the cooked shrimp to a plate or bowl to cool.

Once cooled, dice the shrimp into small, bite-sized pieces.

In a mixing bowl, combine the diced shrimp with mayonnaise, sour cream, celery, cucumber, red onion, lemon zest, and remaining lemon juice. Fold in chopped dill or chives.

Taste and adjust the seasoning with salt as needed.

Slice each avocado in half and remove the pit. Scoop out the skin while keeping the halves intact.

Rub the avocado halves with lemon or lime juice to add flavor and reduce browning.

Sprinkle sea salt and chili powder on the avocado halves.

Stuff each avocado half with about 1/3 cup of the chilled shrimp salad.