Place egg yolks, vanilla, sugar and salt in a medium size metal or other heatproof bowl.
Whisk together until well blended.
Heat heavy cream, milk and 1 Tbls mint leaves in a medium size saucepan over medium heat until it JUST begins to simmer.
(taste for mint flavor, and add more mint if needed; may take up to 3 tbls depending on strength of flavor desired) Temper the egg mixture by slowly whisking in about 1/3 of the hot cream mixture, adding it in a thin stream while whisking vigorously to avoid cooking the eggs.
Then slowly add the egg/cream mixture back into the remainder of the heated cream, whisking to blend.
Heat mixture over medium-low heat, stirring constantly with a spatula, until the anglaise coats the back of the spatula (just at 180F, but be very careful not to exceed 180F or mixture will curdle).
Partially immerse pot in a bowl of ice water to stop cooking.
Strain through a chinacap to remove most of the mint leaves.