Melt the butter in a small skillet over medium heat.
Add the pecans, and cook
until the nuts are coated with the butter and lightly crisped.
Strain the excess
butter into the top of a double boiler.
Add egg yolks, half-and-half, whipping cream,
sugar and vanilla extract.
Set the pan over its water bath.
Warm the custard mixture over medium-low heat, whisking until the mixture is
well blended. Continue heating, frequently stirring up from the bottom, until the
mixture thickens. (Make sure it doesn't come to a boil; the egg yolks should
poach, not scramble.) This process takes about 15 minutes.
Remove the pan from the
heat and pour the custard through a strainer into a bowl.
Chill it thoroughly.
Transfer the custard to an ice cream maker, and process it according to the manufacturer's
After churning, stir in the pecans, and place the ice cream in the freezer
until serving time.