1 Halve and juice grapefruit. Measure 100 ml (approximately a scant 1/2 cup) juice.
2 Peel and quarter garlic.
3 Rinse thyme, shake dry and set aside.
4 In a blender, puree grapefruit and tomato juices, garlic, and peppercorns until frothy. Fill a glass with ice cubes and pour in juice. Season with salt and garnish with reserved thyme.