I do mine very similar, with beer... I never use any tomato in pot roast...
but instead of the garlic, I cover the whole top of the roast with about 1/4 inch of prepared horseradish...
and cook in a 250F oven in a cast iron dutch oven for about 5-6 hours...
The carrots and potatos come out great, as the horseradish turns sweet during the cooking process...
and the onions on the bottom are so sweet!
I make a gravy with the liquid while the roast is resting, prior to slicing...
make a really good sandwich the next day...