Grass-fed Beef Liver With Brown Butter Carmelized Onions and Dried California Plums

Or, more affectionately known in our household as Prune Liver Dinner!

Beef liver is one of the most nutrient-dense foods. How it quantitatively compares to other foods is dependent on how the nutrients are weighted (essential vitamins only, types of fat, etc), whether the comparison is done by mass or isocalorically, and other factors like if the food is actually possible to eat in any reasonable quantity (a cup of dried basil sound tasty?). This talk on nutrient density is great place to start. However nutrient density is measured, beef liver from high-quality sources is going to come out near the top, and so I want more of it in my and my kids' diets.

The only problem is I really don't like beef liver.

I like chicken, duck, and goose liver, especially in pâté. However, having not grown up eating beef liver, I think it's a cultural aversion, or perhaps poor handling and sourcing. With its nutrient-density in mind, I decided to do two things: find out if I could learn to like liver, or at least create a liver dish that I did like; and regularly serve my kids liver, both for their health and so that they think of beef liver as perfectly normal, and perhaps further, even grow to like liver.

This recipe is the result of cooking beef liver two to three times a month for a year. Monday has become our regular liver dinner night. In accordance with convincing the kids they like liver, I get very excited about the liver. "Guess what I'm cooking for dinner!" "Prune liver dinner!" Feign excitement until it turns into real excitement!

Last Monday, the 5-year-old wolfed down her liver, the 2-year-old ate it without complaints (or threats or bribes), and the adults fought over the remainders. I consider this success, and am sharing the recipe.

Step 1: Recipe

Here's the short, no pictures form of the recipe. See further steps for more details.

• ~500 g grass-fed beef liver
• milk
• butter
• cream
• ~400 g onions, thinly sliced
• ~100 g dried plums, chopped
• salt

1. Slice the liver, rinse it in water, and soak it in milk for several hours. Rinse the liver again after soaking, and discard the milk.
2. Cook liver sous vide with 1% salt by mass and butter at 130 F - this step can by skipped if liver is to be fully cooked with the onions
3. Slice onions, brown butter, and caramelize onions in butter and ~0.5% salt by mass of uncooked onions
4. Once onions are fully caramelized, add liver, cook briefly to drive off liquid released by liver during sous vide cooking, but not long enough to raise the temperature of the liver much above ~140 F - if not cooking liver sous vide, add raw liver and 1% salt, and cook until an instant-read thermometer measures the liver and onions at 140 F.
5. Once sufficient liquid has been driven off, add cream and chopped prunes
6. Serve immediately while warm.

Step 2: Inspiration

When first starting this exploration of liver, I looked for inspiration from Thomas Keller. There are liver recipes in Under Pressure -- Milk-poached calf's liver, caraway-glazed cipollini, granny smith apple, dijon mustard, and sauce laurier --, and Bouchon -- Liver and onions with figs.

The milk-poached liver recipe was too complicated for an evening meal served to children. However, I did explore both soaking the liver in milk and poaching the liver in milk (cooking it sous vide both in milk and in cream). Poaching the liver in milk didn't seem to improve the flavor, while soaking in milk definitely did. Soaking liver is suppose to reduce bitterness, remove impurities (like the animal's bodily fluids), and improve taste. In Modernist Cuisine, they claim water soaking should work just as well as milk soaking. There is certainly some blood that washes off when I rinse the liver in water, but I haven't yet explored soaking in just water.

Liver and onions with figs was more my style, especially considering this note about the recipe:

"The sweetness of the onions, of course, goes perfectly with the earthy flavor of the organ meat, and the figs raise the sweetness to dramatic proportions."

This is clearly what I'm looking for in feeding liver to children: increase the sweetness until they'll eat it. Unfortunately, I don't have fresh figs all year round, but thought that dried plums might be a good substitute since dried figs don't rehydrate well and their seeds might be distracting.

Step 3: Grass-fed Liver

My primary source for grass-fed beef liver is Alderspring ranch. When eating liver, I think it's important to get the highest quality. Alderspring is the best I've tasted.

Step 4: Slice and Rinse Liver

Slice the liver into thin strips and rinse it in water. If the liver is frozen, rinse it in warm water otherwise it will turn into milk-liver ice cubes during the next step and not actually soak. Here, I'm using a pound (~500 g) of liver.

Step 5: Soak in Milk

Soak the liver in milk for several hours while refrigerated, then discard the milk and rinse again in water.

Step 6: Cook Liver Sous Vide

Cook the liver sous vide at 130 F with 1% salt by mass and butter. In the configuration shown, the liver will come to temperature in about 45 minutes, or about the same time it takes to cook the onions.

Step 7: Slice and Cook Onions in Brown Butter

Brown the butter. Thinly slice the onions, and cook them in the browned butter with approximately 0.5-0.8% salt by mass of uncooked onions. Here I'm using approximately 400 g of onions. Cook the onions over medium-low heat until they are fully caramelized. It took 35 minutes from the picture of the uncooked onions in the pot to the picture of the cooked onions. Cooking the onions at higher heat doesn't achieve the sweet caramelized taste any faster.

Step 8: Add and Cook Liver

Add the sous-vide-cooked liver to the onions. The cooked liver will have dropped some liquid. Cook until much of the liquid is evaporated, but don't let the liver go much above 140 F. The intention is to drive off some of the water and slightly caramelize the liver before adding the cream.

If not cooking the liver sous vide, add the raw liver and salt at this point, and cook until the mixture reaches a temperature of 140 F. I've found that the dish improves the more delicately I've cooked the liver.

Step 9: Finish With Cream and Prunes

Once the liver and onions are cooked, connect them with some cream. I usually just pour some cream in without measuring; I estimate I used 100 mL. Then, add 100 g of chopped prunes. Having the kids chop the prunes is a great way to get them involved in the dinner, and I can let them "sneak" a few small pieces to add to the overall excitement around Prune Liver Dinner!

Step 10: Serve

Serve while still warm.

Look at those happy eaters!

Step 11: Other Tests

Big pieces of liver, either cooked sous vide or fried, weren't as good as thin slices.

Chopped onions weren't as good as sliced onions.

Poaching the liver in milk or cream wasn't any better than cooking it sous vide with butter and salt. In the images, I'm using a chamber vacuum sealer to vacuum pack liver and milk.

You'd think bacon would be a great addition, but it added a step and didn't improve the dish. I tried some other cured and fried meats (salami, pepperoni, etc..) with similar results -- good, but not worth the additional steps.

I didn't have prunes and once made it with bananas. The result was good, but prunes fit better than bananas.

I didn't have prunes and once made it without any fruit. It was edible, but very livery and the children were not fans.