Salt preserves food, and we've using it in that capacity for thousands of years. But here's a neat tip: Meat and fish aren't the only things you can keep from going rancid with salt curing. It also works with egg yolks. Your friends (the ones with reservations at expensive restaurants anyway) are going to think you're a goddamn food wizard for turning eggs into crumbly pucks of umami, and hell yes they taste delicious. The principle is the same as any other type of curing: Salt wicks away moisture and starts killing off the bacteria that makes food go bad. Sugar is also included because it feeds bacteria in the lactobacillus genus — which seems counterintuitive at first, but lactobacillus are friendly bugs. They show up in cider, kimchi and yogurt and make whatever they're in more acidic, thereby killing even more of that harmful bacteria. Enemy of my enemy and so on.
Chef Elise Kornack decided to jazz things up for this recipe by burying her yolks in a shit-ton of salt and sugar seasoned with bonito flake and bay leaves. Additional flavours or not, you just stick the buried yolks in the fridge for two days so the cure has time to work its magic. Once they're cleaned off, toss them in an oven, a dehydrator or just hang them in cheesecloth if you're very patient. They should come out solid, bright orange and delicious.
Grated over carbonara is one of the best and most obvious uses, but Kornack also suggests using the yolks in salads or on vegetables. Either way, you're going to blow some minds when your dinner guests realise they're eating eggs instead of grated cheese.