Offer this pale green, subtly flavored spread with crisp wheat crackers or tortilla wedges that have been heated under the broiler until crisp.
1. Heat the water and butter in a large skillet. When the butter is melted, add the asparagus and onions and bring to a boil. Sprinkle on the thyme and salt. Cover the pan and reduce the heat. Cook at a gentle bubble for 5 minutes. Remove the cover and stir the asparagus over high heat until all the moisture is evaporated.
2. Combine the cream cheese and sour cream in the container of a blender or processor. Add the asparagus mixture, lemon juice, and Tabasco. Whirl until smooth then transfer to a serving bowl. Cover and refrigerate until thoroughly chilled. Garnish with strips of lemon zest.