Using direct heat and turning frequently, char the peppers on all sides.
Place peppers in a paper bag for 15 minutes.
Remove the skin and seeds, chop finely.
In a stock pot, sauté the onions and garlic in olive oil until golden brown.
Dust with flour to make roux.
Add vegetable broth, bring soup to a boil.
Add peppers, potatoes, and tomato paste.
Simmer for 30 minutes.
Puree soup.
Return soup to a simmer.
Heat half and half and milk until just below a simmer.
Whisk in hot half and half, milk, cilantro, salt, and pepper.
Simmer for an additional 5 minutes and serve.