Eli Zabar, owner of The Vinegar Factory in New York City, believes that with only a few fresh ingredients, you can achieve a full-flavored sandwich. This is one of Eli's favorite recipes.
Cut poached chicken breast into 1-inch chunks. Place in a medium bowl, and add lemon juice. Toss to combine.
Add mayonnaise, tarragon, and salt and pepper to chicken mixture. Stir to combine.
Cut bread lengthwise into 1/2-inch slices.
Place a scoop of chicken mixture between two pieces of bread. Press firmly on sandwich to flatten. Slice sandwich in half or in quarters. Serve.