1. Prepare the Crust:

1. Roast the poblano peppers over an open flame or under a broiler until the skin is blackened and blistered. Place in a bowl, cover with plastic wrap, and let steam for 10 minutes. Peel off the skin, remove the seeds and stem, then dice the peppers.
2. In a large pot, melt the butter over medium heat. Add the diced onion and cook until softened, about 5 minutes. Add the garlic and cumin, cooking for another minute until fragrant.
3. Add the corn, diced potato, roasted poblano peppers, and vegetable broth to the pot. Bring to a boil, then reduce heat and simmer for 20 minutes, or until the potatoes are tender.
4. Using an immersion blender, partially puree the soup until it thickens but still has plenty of texture. Alternatively, transfer 2 cups of the soup to a blender, puree, and return it to the pot.
5. Stir in the heavy cream and season with salt and pepper. Heat through for 5 minutes, but do not boil. Serve hot, garnished with fresh cilantro.