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 into 1/2-inch slices, lengthwise. Place a scoop of chicken mixture between two pieces of bread. Press firmly on sandwich to flatten. Slice sandwich in half or in quarters. Makes 2 servings. Source: "Martha Stewart Living - " S(Formatted for MC5): "by Lynn Thomas - Lynn_Thomas@prodigy.net" Per serving: 722 Calories (kcal); 72g Total Fat; (85% calories from fat); 28g Protein; trace Carbohydrate; 97mg Cholesterol; 546mg Sodium Food Exchanges: 0 Grain(Starch); 4 Lean Meat; 0 Vegetable; 0 Fruit; 6 Fat; 0 Other Carbohydrates Recipe by: Recipe from Eli Zabar; Owner; Elis Vinegar Factory, 431 Eas Converted by MM_Buster v2.0n.