Place the orange juice and sugar in a large saucepan over low heat. Cook, stirring occasionally, until sugar dissolves.
Add the rhubarb, pear, apple and cinnamon stick. Bring to a simmer and cook, covered, for 5 minutes. Uncover and cook for a further 5 minutes or until fruit is tender and liquid thickens slightly. Remove from heat and set aside for 15 minutes to cool.
Spoon compote among serving bowls. Top with a dollop of custard and Serve immediately.