Tamarillo blended with water, milk or both, sweetened to taste and strained. Known in Colombia as tomate de árbol and sold internationally as tamarillo, it is tart and faintly savoury, which is why it takes sugar and why milk suits it. Five minutes, serves five.
Made with water it is sharp and refreshing; made with milk it becomes rounder and much less acidic, which is how most Colombian households drink it. A mix of the two is common and is what this recipe assumes. Taste before you decide on the sugar: tamarillo is more tart than it looks and how much it needs varies a lot with ripeness. Ripe fruit is deep red or orange, gives slightly under a thumb, and comes away from the skin easily; an underripe one is hard, green-shouldered and unpleasantly sour.