Dip the avocado slices into the lemon juice and place on a paper towel to drain. This will help to prevent oxidation.
Chill a large round serving plate. in a circular pattern, leaving the center open for a small ramekin in which to serve the chipotle cream, alternate the slices of tomato, cheese and avocado. Sprinkle the minced tarragon over the arrangements and lightly sprinkle with coarse salt and pepper to taste.
In a small bowl combine together the yogurt, chipotle and adobo sauce and if desired additional salt and pepper. Place the prepared yogurt mixture in center of serving dish. Allow each individual guest to spoon the chipotle cream over the tomato and cheese slices when plating.
Please note: It is important that this salad be served quickly after preparing. If it is allowed to sit to long it will loose its "fresca".