I followed this recipe, with these changes: I omitted the onion, used a mixture of tallow and schmaltz instead of lard, and used the chicken broth in which I’d simmered the beef heart instead of beef broth. I also omitted the tapioca flour. (The garlic was the first garlic of the year from my garden. The cloves are a good size, but there were only 4 on this bulb and the skin has not yet thinned to a papery texture.) Depending on how I decide to use the rest of the gravy, I might thicken it with some guar gum or arrowroot flour or I might leave it thinner.
I warmed some slices of the beef heart in the gravy then topped them with sour cream. Not particular spicy, but excellent flavour.
It was also good on fried eggs for breakfast – I just spooned some cold gravy over the eggs for the last couple minutes of cooking.