Most people think creme brulee is a real fancy dish but it's actually very simple to make. Using a sous vide machine makes it even easier. This is a classic creme brulee and you can take it in a variety of directions depending on the flavors you want.
To get the ramekins at the proper height it is helpful to put a bowl or strainer upside down in the water bath and place a plate or sheet pan on top of it where the ramekins can sit. If you have a lid for your water bath make sure you use it, it will keep the air hot as well as eliminate evaporation, otherwise be sure to maintain the water level throughout the cooking process.
The best depth for the creme brulee is usually less than an inch (25mm) deep, otherwise the inside might not cook all the way through. For deeper creme brulees you may need to increase the cooking time to offset the depth. If your ramekins are touching each other in the water bath it can help to rotate them half way through the cooking process to ensure they cook evenly.
Place an upside down strainer or bowl in your water bath. Top with a sheet pan or plate. Set the ramekins on it and fill the water bath two-thirds of the way up the ramekin. Preheat the water bath to 190°F (87.8°C).
Pour the heavy cream into a pot. Split the vanilla bean and scrape out the seeds, add the seeds and the bean to the cream. Add the cinnamon stick. Bring just to a simmer, stirring regularly. Turn off the heat and let it infuse for 10 minutes. Strain the cream.
Whisk together the egg yolks in another bowl then slowly whisk in the salt and sugar, the mixture should turn glossy and thicken slightly. Slowly whisk in the infused cream. Evenly divide among the ramekins, cover each ramekin with plastic wrap and use a rubber band to hold it in place. Place the ramekins in the sous vide bath with the water level coming two thirds of the way up the side. Cook for 60 to 90 minutes, depending on how thick you prefer your creme brulee.
Once cooked, remove from the water bath and let cool for 15 to 20 minutes. Place in the refrigerator and chill until cold, or preferably overnight.
Spread a thin layer of sugar a few grains thick on the top of the creme brulee and quickly torch until the sugar melts and begins to brown. Add a few mint leaves then serve.