Step 1 Bring the milk, cream, vanilla and half of the sugar to boil in a saucepan over medium heat. Add the lavender, turn off the heat and infuse for 1 minute.
Step 2 In a separate bowl, combine the yolks and remaining sugar. Prepare a bowl of ice water; set an empty bowl on top of the ice water and place a strainer on top of the empty bowl.
Step 3Whisk about one-fourth of the milk-cream mixture into the yolk mixture, being careful not to cook or scramble the eggs. Bring the milk-cream mixture back to a boil and stir in the tempered yolk mixture. Cook, mixing continuously with a wooden spoon, until the mixture coats the back of the spoon, about 3 minutes. Strain the mixture into the empty bowl and chill about 1 hour, stirring occasionally.
Step 4Freeze in an ice cream maker according to the manufacturer's directions. (Makes about 2 1/2 cups.)