In a medium saucepan, combine the whole milk, sugar, and heavy cream. Heat until bubbling around the edges, then remove from heat and add mint leaves. Cover and steep for 1 to 2 hours.

Whisk the egg yolks in a separate bowl until smooth and pale. Set aside.

Reheat the mint-infused milk over low heat. Gradually pour into the egg yolks while whisking to temper them.

Return the mixture to low heat and stir until thick enough to coat the back of a spoon, about 5-7 minutes.

Strain the mixture into a bowl to remove mint leaves, then stir in heavy cream and salt. Refrigerate until fully chilled, ideally overnight.

Churn in an ice cream maker according to the manufacturer's instructions until soft-serve consistency is reached.

Transfer to an airtight container and freeze for at least 4 hours until firm.

Puree the watermelon chunks in a blender, then mix in the sugar and lemon juice until smooth.

Pour the watermelon puree into a shallow dish and freeze. Every 30 minutes, scrape with a fork for about 3-4 hours until fluffy.

Scoop the ice cream into bowls and top with the icy watermelon granita. Optional: drizzle with sparkling rosé.