Make the custard base. In a medium heavy-bottom saucepan, heat the heavy cream and whole milk over medium heat until steaming — do not let it boil.

While the cream heats, whisk the egg yolks and granulated sugar in a separate heatproof bowl until the mixture is pale yellow and thick, about 2 minutes.

Temper the eggs. Slowly pour about 1 cup of the hot cream mixture into the egg yolk mixture while whisking constantly. This gradually raises the temperature of the eggs without scrambling them.

Once combined, pour the egg mixture back into the saucepan with the remaining cream.

Cook the custard. Reduce heat to low and cook the mixture, stirring constantly with a wooden spoon, until it coats the back of the spoon and holds a line when you draw your finger through it, about 170°F on a thermometer. This takes 5-8 minutes. Do not let it boil.

Strain and chill. Remove from heat and stir in the salt and vanilla extract. For an extra-smooth custard, strain through a fine-mesh sieve. Cover and refrigerate for at least 2 hours, or overnight for best results.

Roast the pecans in butter. While the custard chills, melt 3 tablespoons of butter in a skillet over medium heat. Add the pecan halves and toast for 4-5 minutes, stirring frequently, until fragrant and lightly browned.

Add the brown sugar and 1/4 teaspoon salt, stir for 1 minute until the sugar melts and coats the pecans, then remove from heat and let cool completely.

Combine and churn. Stir the cooled butter-roasted pecans (and any butter-sugar mixture from the skillet) into the chilled custard.

Pour the mixture into your ice cream maker and churn according to the manufacturer's instructions, usually 20-25 minutes, until it reaches soft-serve consistency.

Freeze until firm. Transfer the churned ice cream to a freezer-safe container, press a piece of parchment paper directly on the surface to prevent ice crystals, and freeze for at least 4 hours, or until firm.

For the best texture, let it sit at room temperature for 5-10 minutes before scooping.