One of my favorite meals and biggest comfort foods is roast, carrots and potatos. I've been making this for the last 15 years and I don't have a specific recipe - I am always changing and evolving how I make it in search of the perfect one!
The way I have made it recently that has turned out really great is :
I use rump roast - I heard that it's the most tender and it really is. It's never tough. I also use the small red potatos. And the small carrots.
I put all of that in the crockpot with a package (or two) of dry onion soup mix. Instead of water - I use beef broth to fill it up. You could dilute it with some water if that seems too salty.
I cook it for around 8 hours on low. This results in tender meat also!
You get a very moist roast with GREAT flavor.
In the past I used cream of mushroom soup but I like it this way much better.