Bring the water and ½ teaspoon salt to a boil in a large saucepan. While whisking, very slowly add in the polenta. Make sure you add just a little bit at a time while quickly whisking, otherwise you'll end up with clumps. Once all of the polenta is added, continue whisking for 1-2 minutes to smooth out any clumps. Reduce heat to low and let the polenta simmer for 25-30 minutes, whisking every minute or two to prevent sticking.
While the polenta is cooking, char the whole poblano pepper over an open flame. I just set it over a burner and turned it over with tongs every few minutes. Once the skin is completely blackened, move the pepper to a large bowl and cover it with a damp paper towel. Let it sit for 10 minutes to steam. Once steamed, carefully remove the charred skin, de-stem, and de-seed. Then, finely dice the pepper and set aside.
Once the polenta has finished cooking, turn off the heat and stir in the diced poblano pepper, chipotle peppers, chives, olive oil, garlic, and additional salt.