1. Arrange the oranges, fennel and onions attractively on a plate (fennel should be upright, if possible). Scatter olives around and drizzle vinaigrette over.
For the vinaigrette:
1. Place 2 cups of cranberry juice in a sauce pan and bring to a boil. Continue to boil over high heat until liquid is reduced by half.
2. Separately, add the remaining 1/4 cup cranberry juice and the sun-dried cranberries and allow them to plump.
3. While the juice is reducing, sauté shallots in olive oil until soft, but not brown.
4. In a blender or food processor, puree the reduction and shallots until smooth.
5. Place the mixture in a bowl and whisk in remaining ingredients including the oil and softened cranberries. The vinaigrette can be stored, covered in the refrigerator for up to 1 week.