Excellent, with alterations
I made this for the first time last summer, and my family agreed that the corn sauce was amazing, but the filling was underwhelming at best. So I just made it again with several alterations. First I used kale instead of spinach. I also added black beans. I had intended to use one can, but I forgot to buy canned beans, so I cooked up 3/4 cup of dry beans and added those right after the mushrooms were cooked and added 2 cloves of minced garlic and one minced habanero at the same time. Then I mixed in 1Tbs of hot chili powder, 1tsp cumin and 1/4 tsp of freshly ground cayenne pepper. Then I mixed in the kale, which takes a little longer to cook than spinach. I turned off the heat and added the onion, salt and pepper, and as an afterthought, the juice of one small lime.
I did the corn sauce almost exactly, except I doubled the garlic and added the cayenne after it was strained. I remembered reading others didn't strain the corn, and thought I might do it this time, but the mixture in my food processor was a thick paste, and I knew it wouldn't work. Don't think that this sauce will passively strain, you need to work at it to push it through the strainer, but the result is a lovely thick, sweet sauce! I just don't think it would be the same without straining. You will get a little bit of an arm workout, but do it!
I assembled this recipe like a casserole instead of individual enchiladas, and increased the number of servings to 8. I used just enough