In a large saucepan, cover the chicken with cold water. Bring just to boiling, cover, reduce the heat and simmer for 10 minutes or until no longer pink. Cool completely and shred with your fingers. Set aside. In a food processor, finely chop the garlic. Peel and cut the avocado into chunks. Puree with the garlic and the lemon juice; mix in the mayonnaise. Transfer to a bowl and stir in the yogurt and Tabasco. (Processing the yogurt has a tendency to make it watery.) Cover and refrigerate.

In a deep, narrow clear glass bowl, layer the ingredients in the following order: lettuce, chicken, ham, Blue cheese and eggs. Cover tightly with plastic wrap and refrigerate several hours or overnight. Just before serving, spoon the dressing over the salad. The salad can be served as is or the top can be garnished with wedges of tomato or leaves of parsley.