Cut the top and bottom off of each orange. Stand the orange on 1 end on a cutting board and, following the curve of the fruit, cut away the skin and pith of the orange. Cut each orange section out of its pith.
In a medium bowl toss together the orange sections, onion, radishes, and mint leaves. Drizzle with oil and season with salt and pepper.
Ingredients without discrete measurements such as "Salt, to taste" or "Ice cream, optional" are omitted from analysis. This is because amounts can be highly variable and difficult to determine.