Preheat the oven to 180C/350F/Gas 4.
Melt the butter in an ovenproof frying pan over a medium heat, then add the whole satsumas and sprinkle over the sugar. Gently fry for 2-3 minutes, until the sugar has dissolved, then transfer to the oven to roast for 4-5 minutes, or until the satsumas have caramelised.
In a serving bowl, combine the yoghurt, honey and chopped mint.
To serve, place the caramelised satsumas on top of the yoghurt, drizzle over the pan juices and sprinkle over the grated lemon zest.
