alcohol and fat
require extra freezing
time for this custard

previous version, 6 servings
2 c whole milk, 2 c heavy cream, zest of 1 orange, 1 c sugar, pinch salt, 5 yolks, 1 T vanilla, 3 T Grand Marnier
boil milk and cream, add zest, stand 30 minutes; add 1/2 c sugar , salt, return to a simmer, remove from heat; meanwhile beat yolks and remaining sugar until pale and thick; spoon some of the milk mixture into the yolks to warm them; add yolks to milk mixture, stir until slightly thickened, stir in alcohols, chill 8 hours, churn and transfer to a frozen container, freeze 4 hours