Slices the oranges: remove the rind by slicing the ends off the orange, then slicing the rind off in segments. Cut the peeled fruit in quarters lengthwise, then slice approximately 1/4 of an inch thick.
Slice the shallots: peel the shallots, and slice into thin crescents, approximately 1/8 of an inch thick. Combine the sliced oranges and shallots.
Make the dressing: in a separate bowl combine the olive oil, red wine vinegar, lime juice, agave, salt, and tarragon. Whisk until emulsified, then drizzle over salad.