For the Cookie Shells:

1. In a mixing bowl, combine the egg whites with the salt, and whip, adding the caster sugar slowly.
2. In a separate bowl, combine the almond meal with the powdered sugar and pass through a sieve.
3. Slowly add the dry ingredients to the whipped egg whites and, using a spatula, fold in until the batter takes on a smooth, shiny texture. Take care not to mix too quickly or vigorously so your mixture doesn’t collapse. Transfer into a piping bag.
4. On a baking sheet lined with a silicone baking mat, pipe 2-inch rounds and let dry for 90 minutes or until completely dry. Bake at 320°F (160°C) for 14-15 minutes. Let rest for 10 minutes on the baking tray before adding the filling.

For the Sweet Potato Filling:

1. Set circulator to 181.4°F (83°C). 
2. Place all ingredients into a sous vide bag, seal, and cook in a water bath for two hours. Remove, and while still in bag, smash gently with your hands with a kitchen towel until the sweet potato is mashed. Chill the mashed sweet potato in a cold water bath until cooled.
3. Whip the filling with a hand or standing mixer until it takes on the consistency of buttercream icing.

To serve:

1. Pipe a thin layer of the sweet potato filling on the flat side of the macaron cookie, and place another cookie on top to create a sandwich.
2. To prepare the cookie’s surface for the gold leaf, lightly moisten the top cookie with a very small amount of water or egg white. Using a small knife (you’ll want to avoid using your hands), carefully break the gold leaf sheet into small pieces. Using the edge of the knife or a small pastry brush, place pieces on the top of the macaron shell.
3. Use a soft kitchen towel to gently press the gold leaf on the shell’s surface.

Developed by Chef Andrea Vicens. Featured in Sous-Vide magazine Fall/Winter 2018.