I sampled a version of this dip in a Mexican grocery store and had to teach myself to make it! Only 3 ingredients and so easy!. You can make it one day ahead, and serve it with the best chips you can get. Everyone loves this and can't believe how simple it is to make (and how quickly it disappears). Although it uses fresh Poblano chiles, this dip is not hot at all but very creamy and savory.
Always wear plastic gloves when working with chiles. Select dark green shiny fresh Poblano chiles that are available in Mexican specialty markets and many regular grocery stores throughout the Southwest. Rinse and pat dry the fresh Poblano chiles prior to roasting. Only substitute Anaheim chiles if you are unable to find Poblanos because it will change the taste. There are 2 ways to roast the chiles. You can either use tongs to roast them on a gas stove or put them in the broiler. For this 2nd easier method turn the broiler on high and place the chiles in a baking pan just large enough to fit (to make it easy to turn them and have them stay in place). As the chiles blister use tongs to turn them so they are evenly roasted. Once roasted by either method place the chiles in a plastic bag and let them "sweat" for 10 minutes. Then, using gloves, peel off the blistered skin and remove seeds and pith. Rinse the chiles to remove any remaining seeds and set them on paper towels to dry slightly. Chop the roasted cleaned chiles and set aside.
With your fingers crumble the Cotija cheese finely until few or no lumps remain. This cheese may be purchased in a piece or already finely crumbled. If you cannot find Cotija cheese you may substitute Parmesan (not Romano or Asiago) cheese.
Mexican crema (or jocoqui, pronounced "hoe-COKE-key") is usually a thinner consistency than regular sour cream, but either may be used. Stir the crema up with a large mixing spoon and gradually mix in the crumbled Cotija cheese followed by the chopped roasted Poblanos chiles. The dip may be served immediately with really good chips such as Tostitos or freshly made local chips, or you may make and refrigerate the dip up to one day before serving.