8 egg yolks
1 cup sugar (to be divided)
2 1/2 cups heavy cream
1 1/2 cups cold milk (to be divided)
1/4 teaspoon salt
2 ripe bananas, peeled, chopped
1 cup California walnuts, chopped
In a large bowl, combine the egg yolks and 1/2 cup of the sugar and whisk together for a moment. Set aside. In a large saucepan, combine the cream, 1 cup of the milk, the salt and the remaining 1/2 cup sugar. Over medium-high heat, bring to just below a boil. Remove from heat and gradually add the hot liquid to the egg yolks, whisking constantly.
Pour the mixture back into the saucepan. Cook over medium heat, stirring or whisking constantly for 10–12 minutes, or just until the mixture thickens slightly and you begin to see wisps of steam rising. It should not boil. Remove from heat and immediately pour into a clean bowl. Stir in the remaining 1/2 cup cold milk, then stir in the chopped bananas. Refrigerate for several hours or overnight, until thoroughly chilled.
Stir in the chopped walnuts in the last five minutes of churning. Freeze the mixture in an ice cream machine, following the manufacturer's instructions. Alternately, if you do not have an ice cream machine, and your home freezer maintains a temperature of about 0º F, place the chilled mixture in a bowl in the freezer. Every 30–45 minutes, beat it vigorously with a wooden spoon, breaking apart the frozen edges, stirring them in, and beating until the ice cream is smooth. Continue until the ice cream is too stiff to beat. Keep frozen until ready to serve.