Preheat the oven to 300F. Wash the peppers very well and dry them. Rub the peppers with salt and olive oil. Put the poblanos on a baking sheet and cook on each side for at least 15 minutes. The idea is to remove the skin of the pepper.
Meanwhile, put the chicken, tomato paste, sour cream, chives, cheddar cheese and coriander into a mixing bowl. Stir with a spoon until all the ingredients are well incorporated.
Remove the peppers from the oven when they are still warm and put them on a kitchen cloth. Rub them until you have removed all the skin of the pepper. You can do it with the help of your hands or a fork. Be careful not to break them.
When you have removed the skin, with a sharp knife, open a segment of the pepper and extract all the seeds. They are ready to fill.
Put the filling inside the peppers with a spoon, sprinkle with a little Parmesan cheese (this step is optional). Bake for 25 minutes or until the cheese is browned.