After seven enchanting years in New Mexico, I became part native. Especially my stomach. Early fall was my favorite time, in part because the end of another hot summer always brought a sweet relief, but mostly because of a certain aroma that wafted up and down the Rio Grande Valley this time of year. The large-scale roasting of green chile fills the air with a magic pungency that grounds you to that arid landscape as autumn foliage and cider do in New England. Green chile has transformational powers on food. It can turn a cheeseburger into a green chile cheeseburger, or scrambled eggs into green chile scrambled eggs. This simple modification sounds elementary, but results in a quantum leap in flavor. And then there is green chile the main course. A New Mexico green chile stew is brothy and nuanced, like the evening breeze after a monsoon rain. But while …