This salad keeps well, and the tarragon flavor only gets better if the salad has a few hours to rest. That makes this a wonderful make-ahead side dish with hearty robust flavors.
In a large bowl, combine shallots and vinegar. Set aside.
Rinse lentils and place in a small saucepan adding enough water to cover by 2 inches. Bring to a boil, reduce heat and simmer 15-20 minutes. Drain well and add hot lentils to shallots. Add the cooked kamut groats. Season with salt and pepper.
Add remaining ingredients, adjusting salt, and pepper. Check for acid balance adding more oil or vinegar if necessary. Refrigerate until ready to serve.