Roast the Walnut Pieces (1/2 cup). Set aside.
Place Maple Syrup (3/4 cup) in a 4 quart pot over medium hear to reduce down to 1/2 cup. Takes about 8 minutes, stir occasionally.
Once syrup has reduced, pour in Heavy Cream (1 1/4 cup) and Milk (1 1/2 cup) . Syrup will stiffen up but continue to stir over medium heat until mixture us warmed through and smooth.
While syrup mixture is warming, whisk Egg (4) a medium bowl.
Temper the eggs by pouring about a 1/4 cup of the syrup and cream mixture into yolks while whisking. Continue adding a little syrup and cream mixture until eggs are at temp. Pour egg mixture back into pot and stir over medium heat until a thermometer reaches 170 degrees F.
Pour custard over a strainer into a bowl. This will collect any bits of egg that didn't incorporate. Cover bowl with plastic wrap and refrigerate 4-5 hours until completely chilled.
Place custard into ice cream maker and churn.
Once ice cream is starting to harden, add the roasted walnut pieces.
Place ice cream into freezer safe containers and chill until desired consistency. Enjoy!