• In a heavy sauce pan, bring milk and cream boil for 6 minutes over moderate heat,
  
• then remove from heat and whisk in dulce de leche until dissolved. Whisk in vanilla and transfer to a metal bowl. Do a quick chill in an ice bath for 15- 20 minutes or chill it in refrigerator for overnight, I like to do overnight chilling.
  
• Next morning make ice cream in ice cream maker according to manufacturer’s instructions.
• Transfer ice cream to an airtight container and put in freezer to harden, at least 1 hour.

If you don't have ice cream machine: try this method.

• First freeze a baking dish while you are preparing the ice cream mixture. Pour mixture into frozen baking dish, freeze for 45 minutes. Take it out, break up frozen bits with whisk or spatula. Repeat this process at 30 minute intervals until it’s nearly impossible to break apart anymore. Scoop into Tupperware containers and place in freezer until ready to serve