Per 4-oz. serving of beef liver (approximately one 4-inch by 4-inch slice)
If you're looking for a way to get lots of protein without lots of fat, opt for kidneys, which contain a pissload of B12, riboflavin and iron, as well as healthy amounts of B6, folate and niacin.
Kidneys are usually consumed in beef, lamb and pork form, but if you're just easing into eating them, we suggest trying beef kidneys, which have a milder flavor. They're also the easiest and cheapest to prepare.
The best kidneys are plump, glossy, and free of discoloration or strong odors. Choose kidneys deep red in color, unless you're going for veal, which look more tan. Rinse them in cold water, remove the outer membrane and slice them in half (if you don’t want a strong flavor, you can soak in water for a few hours with some salt). They're often sauteed with butter and olive oil, but also commonly baked into kidney pies or casseroles.
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