Watermelon Cucumber Granita

Bahan-bahan (6 porsi)

• 4 1/2 cups seedless watermelon (peeled and cubed, about 1/2-inch cubes)
• 1 1/2 cups cucumbers (peeled, seeded, and chopped (English or Persian cucumbers))
• 1/4 cup monk fruit sweetener ( or sugar)
• 1 tablespoon fresh lime juice
• Thin cucumber slices (optional for garnish)