Homemade Enchilada Sauce

I hate it when something simple takes years to achieve. These days, I’ll take any simple pleasures I can get, and this was an easy one.
For as long as I can remember I’ve wanted to make my own enchilada sauce. It’s always been a mystery to me that comes only from a can. And yet, there’s something luscious and familiar and screaming “I’m homemade” when I eat enchiladas from Rudys. The sauce is dark and very specific to Rudy’s – I’ve never tasted a sauce like it at any other Mexican restaurants.
I know from making chili sauce for Tamales that I can use dried peppers and a blender to make a nice thick flavorful sauce if I can just figure out what else to put in it. Here’s what I tried:

1 Ancho chile
3 gaujillo chiles
2 New Mexico chiles
6 California chiles
2 cups chicken broth
1 cup water
1 tsp cumin
1 tsp salt
1 tsp sugar

Break up the dried chiles and remove the stems and seeds. Tear or chop them into pieces and place them in a pan. Roast for 1-2 minutes with heat, but don’t let them smoke or burn. Add 2 cups chicken broth and and bring liquid near boiling but just get it hot and then turn off heat and let them sit for 20 minutes until then get soft and swell in the liquid.
Add the soft mix to a blender. Add cumin, salt, and sugar, and blend to a fine puree (add water or broth if too thick).
Heat 2 Tbl oil in a pan and add 1 Tbl flour. As the flour is sizzling, stir in the sauce. until it starts to bubble. Add more liquid to get the desired consistency.
Even with three cups of added liquid, I found I could have added another half cup of water, as the sauce was still thick, but it did a wonderful job of coating the tortillas while making enchiladas, and when I topped the enchiladas, it was thick enough that it didn’t run down the sides. So even though it was thick, it worked well and had good working consistency.
I made 8 cheese enchiladas (cheddar cheese, black olives, white onions, baked at 425 F, 25 minutes) and had about a cup of sauce left over.
The sauce tasted pretty good, but was a little bitter. Not sure what it was missing.