This happened because I used a jar of onion and garlic jam that didn't have enough vinegar. I am nervous to just add vinegar to the gravy but maybe I should…
Add vinegar, a bit at a time, stirring it in well to blend. You could also add a touch of tomato paste. I'd probably add a bit of both. ;o)
Thanks for your response
A bit of unsweetened chocolate or cocoa can be helpful in these situations.
Or, divide your current batch of gravy in two, saving half for another use.
Then proceed to doctor the retained half by adding vinegar as AJ suggests, maybe some broth, wine, tomatoes mushrooms, onions. These elements will both reduce and diffuse the sweetness.
Please let us know how it works out.
Apparently I'm the only one (what, again?), but it seems to me that adding sour elements is more apt to emphasize the sweetness than otherwise. Then again, this pot roast recipe is seemingly headed in directions beyond my ken.