In a 3 quart sauce pot add onions, potatoes, carrots, celery, garlic salt, and bay leaves and saute over medium heat 10 minutes, stirring often. Add stock and bring to boil; then lower heat, cover, and simmer for about 15 minutes.
Add artichoke hearts, sherry, and saffron to soup pot and continue simmering for 5 minutes.
Now stir in the lemon juice, orange juice, and orange & lemon zest, simmer for another 5 minutes. Season to taste with black pepper. Remove and discard bay leaves, and take a hand held blender to the soup and puree till everything is blended.
At serving time ladle soup into bowl and arrange 4 quartered marinated artichokes in the center of the bowl along with 1 heaping tsp of sour cream. Drizzle 1 tsp of the marinated artichoke oils over the soup and serve.