In a stand mixer combine whole milk, sugar and salt. Whisk on high till sugar dissolves.
Add cream and mint extract, whisk on high (start slow and build to avoid splatter) until the mixture is creamy and fluffy like whipped cream.
Cover and stick in the fridge for an hour.
Remove from fridge and transfer to your ice cream maker. Churn for about 15 minutes. Then add chocolate chips. Churn for a few more minutes.
If fairly firm you can pour right over the brownie/hot fudge mixture, then cover and pop in the freezer for about an hour.
If it's not hard enough enough, pop it in the freezer for an hour or so till it's hard enough to spread over the brownie/hot fudge mix without leaking all over the place and down the sides.
Freeze for at least an hour or overnight.
Take out about 10 or so minutes before serving so the brownie/hot fudge portion thaws enough to spoon through. Otherwise you'll break your teeth!
Serve with a big old minty smile!