Melt butter in a medium saucepan; add onion and leeks and cook, covered, about 10 minutes, or until tender. Uncover and cook until leeks are very soft, about 5 minutes, adding garlic at last minute.
Add broth, artichokes, potatoes and thyme and simmer 15 minutes or until potatoes are tender. Add milk and TABASCO® Sauce and simmer 5 minutes longer. Remove from heat and discard thyme.
In a food processor or blender, purée soup until very smooth. Serve hot or cold, garnished with parsley.
Makes 8 to 10 servings.
From THE TABASCO® COOKBOOK ©1993 by Paul McIlhenny with Barbara Hunter. Used by permission of Clarkson Potter Publishers.