I'm planning a roast beef smoke this weekend for a 50th birthday dinner for my dad. For the beef, I'd like to make an au jus to dip the beef on a bun in. From what I gather, I need to add a drip tray under the beef in the smoker. I was thinking of adding beef broth, beer, chopped carrots and onions to the mix and let the drippings do their thing. Am I off base here? Or is this an appropriate method?