There is a filling recipe, I think on allrecipes, where you throw the chuck roast and spices into the crockpot so you can work on the other parts.
I bought a chuck roast around Christmas and was going to try my hand at it, but we had guests. In my initial excitement I thought about having them help, but a table full of inlaws who don't know how to make tamales trying to make a batch is simply inviting disaster.
I think I will try again during a lower-pressure time. My husband has a ton of leave that he has to take - maybe I will get him to take a couple of days off and it can be a labor of love.