1. Heat the milk with the cream and the sugar. Remove from heat before it comes to a boil, add the flower petals, and cover. Allow to infuse for 1-2 hours.
2. Pour the infused liquid through a strainer into a bowl, squeezing out the petals to extract all of their flavor. Compost or discard the flower petals. Reheat the milk/cream mixture over medium heat to just before boiling, then set it aside.
3. Beat the egg yolks with a fork or wire whisk. Slowly pour 1 cup of the the warmed, infused milk/cream into the egg yolks; whisk constantly while you do this so that the egg yolks don’t cook.
4. Pour the tempered eggs back in with the rest of the milk/cream and place over medium heat. Stir constantly with a wooden spoon, scraping the bottom of the pan as you do so, until the custard thickens and coats the back of a spoon (this will take several minutes).
5. Remove from the heat immediately and pour the custard through a fine mesh strainer. Stir the custard thoroughly, transfer to an appropriate container, then cover and chill completely in the refrigerator (overnight is best) before proceeding to make ice cream according to your manufacturer’s instructions.