Using a strainer, rinse the quinoa under cold water. Add quinoa, water, and salt to a medium saucepan and bring to a boil. Cover, reduce heat to low, and simmer for 15 minutes, or until quinoa is tender. Remove from heat and let stand for 5 minutes, covered. Remove lid and fluff with a fork. Transfer to a large bowl and let the quinoa come to room temperature.

While the quinoa is cooking, grill the corn on outdoor grill or on an indoor grill pan until lightly charred. Carefully remove kernels from the cob with a sharp knife and set aside.

Char the poblano peppers over a high flame on the grill or over a flame on a gas stove. Use tongs to rotate the pepper every couple of minutes or so until all sides are black. You can also char the peppers under the broiler in the oven. Place the peppers on a baking sheet that has been lined with aluminum foil. Broil poblanos for 5 minutes, or until the skin is blackened and blistered. Carefully flip them over and broil for another 5 minutes, or until the skin is blackened and blistered.

Once peppers are blackened, place them in a plastic bag or paper bag and seal. Allow them to steam in the bag for about 10 minutes to loosen the skin. Pull and rub off as much of the loose black skin as possible. Chop up the peppers.

Add the sweet corn, poblano peppers, cilantro, cotija cheese, and avocados to the quinoa.