Melt margarine in large stock pot
Add onions and celery, sauté until onions are translucent, approximately 5 minutes
Add flour to create roux, cook over medium heat for 5 minutes
Add green chilies, potatoes, cumin, black pepper and salt. Sauté 4 – 5 minutes
Add oregano, bay leaf, water and chicken base. Bring to a boil, reduce heat and simmer
Simmer for 30 – 45 minutes or until potatoes are tender
In a separate pan, bring half & half and buttermilk to a simmer and add to soup
Season with salt and pepper
Remove bay leaf
Add shredded Monterey jack cheese, tortilla strips and chopped cilantro to soup.