Heat heavy cream, whole milk, salt and sage over moderate heat. (Also add sugar at this point if substituting for honey.) Bring to a simmer, then remove from heat, cover and let sage steep for 1 hour. Remove sage.Bring cream mixture back up to heat, until just simmering, then very slowly pour a third of the cream mixture into egg yolks while whisking constantly. Pour this combined mixture back into pot while whisking and heat until the cream coats the back of a spoon, or until it reaches 170°F. Remove from heat then whisk in honey and vanilla extract.Let chill completely in fridge. Churn in ice cream maker and let freeze for at least 2 hours before serving.