Mascarpone makes a smooth, rich sherbet. If you are not making your own mascarpone, be certain to use only a very high-quality product, or the cheese may separate in Step 2.
Place the water, lemon thyme, sugar, and lemon juice in a saucepan. Bring to a boil. Remove from the heat, cover, and set aside to steep for 1 hour.
Whip the egg yolks for 1 minute. In a saucepan, bring the honey to a boil. In a slow steady stream, add the honey to the egg yolks, beating constantly, until cooled.