I see chile relleno tacos occasionally in the smaller Mexican fondas (small, sit-down restaurants): it’s not a street item. This makes for a hefty taco—as well as a goopy, saucy and rich one, which must be double-wrapped. A single taco is usually enough for most people for a meal. Poblano chiles are used to make chiles rellenos in Mexico, but be aware that they have a tendency to be unexpectedly spicy. Long, pale-green Anaheim chiles are always mild and tasty.