I was going to double the recipe but when chopping the tomatoes I thought it would be way too much. I decided to use eight or nine tomatoes instead of six and kept most of everything the same. I had never used ancho chiles before so it was fun to try something new. I had also never roasted jalapeños before so that was fun to try, thought it wasn't really easy to peel the skin off.
I'm realizing right now that the book recipe slightly differs from the website in that the book only calls for 1 ancho chile and 2 jalapeños while the website calls for 2 ancho chiles and 4 jalapeños. Without having looked at the website I added an extra ancho chile and jalapeño anyway, so I recommend following the website recipe.
This is a chunky salsa, but if you prefer yours thin I think you could use a blender or food processor to liquify it some and it would be great too. It was a bit on the mild side for my tastes but it could probably easily be spiced up with more jalapeños if desired. My salsa seemed a bit bland at first so I added a couple extra teaspoons salt and extra chili powder, and I thought the flavors increased after it sat for a few hours. This morning I realized I think I forgot the garlic, oops! Overall it was a tasty salsa.