It's very strange to see a food section on this forum... I just noticed it, and I love cooking =)
Anyways, If I was making a stew like this what I would do is replace part of the water with a stock. Like 4 cups water, I'd do 2 cups water 2 cups stock. Personally I'd use chicken stock for more roundness in flavor, if I *did* go for beef stock, I'd probably do 3 parts water to one part stock.
Alternatively you may try adding some beef bullion to the water, just be careful as it can get salty, and 'artificial' tasting.
Also I would most definitely add shallots to this recipe, and I would roast the potatoes at high temp and add them later in the recipe for texture's sake. You didn't mention how you were preparing the potatoes so I assume just boiled?
If you didn't want to just add more basil you could add in addition to the basil something else... Probably marjoram for this recipe.
I hope any of this was helpful =)