Place grapefruit sections in a single layer on a baking sheet; freeze until firm.

Remove berries from container and coarsely chop.

Combine frozen berries and frozen grapefruit in the container of a food processor fitted with the steel blade. Process with on/off flicks until finely chopped. With motor running, add 1/4 cup milk. Add smooth and creamy.

Serve at once or transfer to freezer container and store in freezer.