I used to work there. All the meat comes in frozen plastic bags. You heat them up in a hot water bath before putting it on the hot line.

For the prices these days it really doesn't make sense unless there's a specific item you like from Taco Bell.

I'd rather go to chipotle where they actually put their meats on a grill and prepare everything. I'm not saying it's not a fast food chain, but I've noticed their ingredients are less processed and more fresh.