Plenty of people put soy milk in their coffee, but soy sauce? John Ulaszek, who also goes by the DCist Flickr contributor pseudonym F1.4, was eating breakfast at what he describes as one of his favorite restaurants in Northern Virginia over the weekend, when he had an experience that makes us a little queasyThe ever attentive waiter noticed my empty cup and promptly topped me off – by now I was rockin the caffeine, the…