OK, I didn't have the guajillo chiles so did a search and found that
Ancho chiles were a good substitute. I did seed them. We really like spicy but this was, well, wow. And we both agreed that there was something missing. I don't know if I can explain it but maybe a little bit of sugar in it? You know, 1 tsp. sugar in the cooking sauce in the stir fry or when my potato salad just wasn't perfect and Grandma said..."Sprinkle a little bit of sugar in it". I have learned that when I cook, and especially with tomatoes or tomato sauce, checking the seasoning that if it seems "flat" it doesn't necessarily need salt. Maybe a pinch of sugar. I don't know, something was missing. But I love the texture of the chicken and would love to try different things with the method.