Special equipment: an instant read thermometer, rolling pin, food processor
Preheat the oven to 400 degrees F.
Trim the fins from the Arctic char. Place the chives, parsley, lemon slices, rosemary, and lemon zest into the cavity of the fish.
Whip the egg whites and cold water with a whisk until they form light peaks. Add the kosher salt and mix well with your hands. The texture should be like damp sand. Invert a baking sheet, the length of which is 2-inches greater than the fish, and spread 3 cups of the salt mixture on the baking sheet as big as the outline of the fish.
Place the fish on top of the salt and cover completely with the remaining 6 cups of salt (you may not need all the salt). The salt should be at least 1/2-inch thick all around the fish. Bake for 25 minutes or until an internal temperature of 140 degrees F is reached.
Let the fish rest for 5 minutes. Crack the salt with a rolling pin and remove the chunks of salt. Peel back the skin and remove the fish from the bones. Serve with Saffron Aioli.
In a food processor combine the egg, lemon juice, garlic, and mustard. Puree until well combined, scraping down the sides of the bowl.
While the food processor is running slowly, pour in the vegetable oil. The mixture will thicken as it emulsifies. Add the saffron, kosher salt, and orange zest. Store covered in the refrigerator for up to 4 days.
Consumption of raw or undercooked eggs, shellfish and meat may increase the risk of foodborne illness.