Adapted from this Bon Appetit recipe.
Equal amounts salt and granulated erythritol (or xylitol). (Enough to cover the eggs in two layers of same thickness as the eggs)
Flavorings of your choice (citrus zest, herbs, spices, etc).
Mix together your salt and sweetener and flavorings.
Spread a layer of this mixture that is twice as thick as your egg yolks into your container. Make sure it is big enough to hold all your yolks spread in one layer.
Make little dips in the mixture to nestle the yolks into so that they stay put and don't roll into each other.
Separate the yolks from the whites, and carefully add a yolk into each dip in the salty-sweet mixture.
Cover all the yolks with the same amount of the curing mixture as was in the first layer, making sure to cover each yolk completely.
Put them into the fridge for 48 hours.
Remove from the curing mixture and gently rinse the mixture off of each yolk. They should be glossy and firm but still tender.
Put them on a drying rack and dehydrate at 140F for 3 hours, or put them in an oven at 150F for 2 hours.
This recipe gives your a slightly flattened yolk, which is not a problem unless you want a perfectly spherical yolk, in which case check out the recipe below.
Follow the same recipe as above, but do NOT remove the yolks from the egg. Surround the whole eggs (in shell) in the curing mixture and place them in the fridge for 2 -3 weeks (small eggs take 2 weeks, larger eggs take 3).
Discard the shell and egg whites, and continue dehydrating the yolks in the manner described above.
This is the best method for making confit yolks for mooncakes. If you want to make a fusion mooncake, check out my Chocolate Truffle Mooncakes recipe.