1/2 pounds cherries, pitted
1 cup sugar
2 1/2 cups heavy cream
1 cup whole milk
1/2 vanilla bean, split, seeds scraped and reserved
8 large egg yolks1 teaspoon lemon juice
1. Make the cherry syrup: Place 1 pound pitted cherries and 1/3 cup sugar in a small saucepan over medium heat and cook until cherries soften - about 10 minutes. Run the cherries and any liquid through a food mill, strain the mixture, discard the solids, and return the liquid to the pan. Cook the cherry mixture over medium heat until it reduces to about 1 cup - 8 to 10 minutes. Transfer to a small bowl and cool completely.
2. Make the ice cream base: Fill a large bowl with ice and water and place a fine sieve over another medium-sized bowl; set both aside. Combine the cream, milk, and vanilla bean and seeds in a medium saucepan and cook over medium-high heat until mixture just comes to a boil. Whisk the egg yolks and remaining sugar together in a large bowl until thick and pale. Whisking constantly, add the hot milk in a slow, steady stream to the yolk mixture. Return the mixture to the saucepan and cook over medium heat, stirring constantly using a wooden spoon, until the mixture coats the back of the spoon - about 2 minutes. Strain the mixture through the fine sieve into the bowl and place bowl in the prepared ice bath to cool.
3. Make the ice cream: Cut the remaining cherries in half, toss with the lemon juice, and set aside. Once the ice cream base is completely cool, stir in the cherry syrup and the food coloring, if desired. Process in an ice cream maker according to manufacturer's instructions. Fold in cherry halves, transfer to an airtight container, and freeze until solid. Ice cream will keep for up to 1 month in a freezer.