Pour the cream into a saucepan set over medium heat.
While the cream is heating up, mix the sugar and salt in a large mixing bowl, add in the egg yolks and whisk together.
Stir the dried porcini mushroom powder into the cream, stirring until just before the mixture comes to a boil. Remove the cream from the heat and begin tempering the eggs by slowly pouring from the saucepan into the mixing bowl in a steady slow stream.
Once it’s incorporated, pour the mixture back into the pan and return it to medium heat. Continuously whisk the mixture, monitoring the temperature using an instant-read or infrared thermometer.
Once it’s reached 185°F, quickly take it off the heat and strain it through a sieve into a bowl. Carefully pour that into your serving bowls and set aside in a cool place to set.