See Salt Cure for Fish Recipe. The scallops must be cured the day purchased and are best eaten that day. They'll still be good the next day (not as good though). I wouldn't eat them any later than that.
1 to 2 whole scallops per person
Large sushi grade scallops (about 5 to a pound), as many as you want
Citrus Sauce (about 1/4 teaspoon per scallop slice)
Avocado (as much or as little as you want)
Black Salt Flakes (use very sparingly - the scallops already get a good bit of salt from the cure)