7-8 lbs of seedless watermelon, cut into 1“ pieces (should be about 3 lbs or 8 cups)
1 1/2 cups pomegranate juice
1 cup fresh raspberries
leaves from a few sprigs of fresh mint
1/4 cup fresh lime juice (about 2 large)
1 cup sugar
Blend the watermelon with the juice, raspberries, and mint until it's a smooth puree. Mix the lime juice and sugar and pour into a large bowl with the fruit puree. Stir until the sugar is all dissolved, and taste for balance.
Pour into a 9×13 pan and set in the freezer. After 45 minutes, stir and break up any large crystals. Repeat every 15 minutes until the pan is full of fluffy ice (about 2 hours total).
source: Fiesta at Rick's - Rick Bayless