1. In large pot, cook bacon until crisp.
2. Transfer to paper towel and set aside.
3. Discard all but 1 tablespoon fat from pot.
4. Add carrots, poblanos, onion, jalapenos, garlic and cumin; sauté until golden brown.
5. Add potatoes, chicken broth and salt. Bring to boil.
6. Reduce heat to maintain gentle simmer, cover pot and cook for 25 minutes; or until potatoes are tender.
7. In bowl, gradually whisk milk into flour until mixture is smooth.
8. Slowly whisk milk mixture into soup.
9. Cook over medium heat, stirring occasionally, until soup is thickened, about 12 minutes.
10. Remove pot from heat.
11. Add cheeses, stirring until melted.
12. Crumble reserved bacon.
13. Ladle soup into bowls and top with bacon and green onion.