1. Warm the half-and-half or cream with the sugar and salt in a small saucepan.
2. In a medium bowl, whisk together the egg yolks.
3. Make an ice bath by nesting a metal or glass bowl in a larger bowl that’s partially filled with ice and some water. Set a mesh strainer over the top.
4. When the half-and-half mixture is very warm, gradually add it to the yolks, stirring constantly with a whisk as you pour (to avoid scrambling the eggs). Scrape the mixture back into the saucepan and cook over medium heat, stirring constantly with a heatproof spatula, just until the custard thickens and coats the spatula. (Do not boil.)
5. Immediately strain the custard into the bowl in the ice bath and stir until cool.
6. Pour the custard into a blender and add the honey, ricotta, and grappa or kirsch (if using). Puree in the blender until the mixture is very smooth, about 30 seconds. Pour the mixture into a container, cover, and chill thoroughly.
7. Add the lemon juice, then churn the ice cream in your ice cream maker according to the manufacturer’s instructions. When done, stir in the candied citrus and nuts, and transfer to a container. Cover, and store in the freezer until ready to serve.