Place the poblano chili directly over a gas burner on high, or under the broiler. Turn as each side blackens, it will take about 8-10 minutes total. Remove poblano from the heat and place in a bowl, then cover tightly with plastic wrap. Allow to steam for 15 minutes. Rub off the blackened skin with a paper towel. Remove seeds and chop into pieces.
Heat the tablespoon of olive oil in a soup pot over medium heat. Sauté the onion and garlic for about 3 minutes until the onion is translucent.
Strip the corn kernels from the cobs. Reserve 1 cup.
In a blender place corn kernels, except reserved cup, onion and garlic, corn starch and 1 ½ cups of milk. Blend until smooth.
Strain through a mesh strainer and cheesecloth directly back into the pot. Stir in the remaining milk and bring to a simmer.
Add the roasted poblanos and simmer for 10 minutes. Taste and add salt as desired.
Stir in reserved corn kernels right before serving.
In a single serve blender or mini food processor, process the cilantro and quarter cup of olive oil. Drizzle over individual bowls of the corn soup.