But surely you leave your meat to rest under foilfor at least 30 minutes, vpv? And you presumably only cook it rare like a good gentleman?
In such circumstances, there should always be a good quantity of juice released, which is indispensable in the gravy.
I'm not sure how I feel about adding jam to gravy, but when feeling playful, I have occasionally been known to add a spoonful of Marmite to it.