RECIPE: Bone Marrow and Black Trumpet Compound Butter

Compound Butter is one of the most brilliant ways to keep and store fresh flavors throughout the cold of winter, when the dearth of mushrooms and fresh herbs might otherwise cause one to go insane. Of course, dried and rehydrated mushrooms may be used for this recipe as well, but why not preserve fresh when you can?  The concept is simple.  Using the matrix of room temp butter, you make a mixture of sorts, and then store it in the freezer in a way that makes it easy to use small amounts at a time. It can be used on steak, vegetables, in dishes, as a finishing butter for sauces, or simply spread on toast for any time.

I like to use what we took to calling the scarborough faire mix--this is a mix of equal volumes of diced herbs from Simon & Garfunkel: parsley, sage, rosemary and thyme.  When I ran the kitchen at Ulterior Restaurant and Bar in Santa Cruz, we found that this mix would send different herbal flavors to the front of the palette depending on the mushrooms used in the recipe.  For me, this recipe particularly brings out the parsley.

For the Mushrooms
1 # black trumpets, fresh, split and thoroughly cleaned
1 ea shallot, diced carefully*
1 ea garlic, clove, minced
2 T beef tallow drained from roasted marrow pan

*Shallots are temperamental.  Try to slice in a grid formation with a very sharp knife. Cut bulb in half, leaving root end intact, slice planes parallel to cutting surface, slice vertical lines from just before root end to tip, then slice tiny squares. DO NOT “mince” & mash them… they will be bitter and angry at you and that is not the goal here, friend.  (In faux french accent: You must caress the shallot with your perfectly sharp knife for optimal flavor.)

For The Butter
1 # butter, grass-fed, salted, room temperature (pliable, but not in the least bit melted)

For the Marrow
2 ea marrow bones (split femurs)
1 T Scarborough faire mix (parsley, sage, rosemary and thyme, see above)


Cook the Marrow

1. Pre-heat oven to 375°F
   
2. Salt marrow bones generously, and place in hot oven to roast, open face up.
   
3. Bone marrow wants to be jelly, but not so cooked that it begins to shrink away from the bone completely. About 145°F internal temp. Let rest for 5 minutes, and scrape contents from bones into a fine meshed sieve to drain excess tallow.
   
4. Add to this tallow the tallow from the pan.  [This is delicious fat for cooking any mushroom any time and will keep for seasons in your fridge. Be careful getting this onto any fabric, carpet, etc. Tallow is a very hard fat when cooled, and can be nearly impossible to remove. Same goes for the drain. Use paper towels to clean all the tallow off of pans before letting any into the sink. It’s bad for your drains!].
   
5. Cool marrow completely, and then chop into small bits.
   

Cook the Mushrooms     

1. Dice black trumpets to very, very small bits. Do not puree, however.
   
2. Heat marrow fat to just-smoking in the pan. Add shallots and garlic and cook for 10 seconds, but do not burn them! Add diced trumpets and cook until water is gone, and mushrooms are beginning to pop and sizzle.
   
3. Remove from heat and cool completely.
   

Storage

1. When ingredients are cooled, and butter is room temperature soft, put everything together in a medium bowl, add herbs and mix with a rubber spatula to completely combine.
   
2. Prepare a sheet of plastic wrap (or double it up if it is thinner), by laying it out flat on a larger surface, counter or table should do.
   
3. Spread compound butter mixture on the plastic wrap from about 4 inches from either end, in a long even bar.
   
4. Carefully wrap the plastic around the butter, push out any air that is trapped between the butter and plastic; grasp the ends of the now closed plastic wrap cylinder, and twist, and then using the friction of the table, slowly drag the log toward you, causing the ends to twist and tighten, and the log to become uniform and evenly thick, like a snake.
   
5. Place this log in your fridge to cool, and when completely cool, 4 hours to overnight, unwrap from plastic, and working quickly, slice small 1-2 Tbsp disks, about .25 inches thick, and freeze on parchment on a cookie sheet.
   
6. When these are frozen, you can toss them together in a bag, tupperware or any container and keep in the freezer for months, especially if you vacuum seal them (while frozen). Alternatively, spoon heaping Tbsp mounds on parchment and freeze in this manner, depending on your intent for using it later.
   

Equipment Needed
1 roll plastic wrap
1 small saute pan
1 cookie sheet

How to use Compound butters:
      Once you have your mixture of butters there are a number of things you can do with is from spreading it on toast (allow it to heat to room temperature), finishing your vegetables with it at the very end of cooking before service; place it under the skin of roasted chicken (we did this with individual chicken thighs, and the result was a beautiful roasted thigh with black trumpets neatly tucked under the skin! Delicious!); use it in a roux with flour as you would any butter, finish a sauce with it as you would any butter, eat it on crackers etc.
      Compound butters can be made with just about anything, so long as the water content is low and the mixture is fridge-cold before you mix with room temp butter and follow the steps above: cooked apples, cinnamon, and brown sugar; candy cap mushrooms, just herbs alone, spice blends, other fruits, dried fruits, minced nuts, etc.  The list is inexhaustible... don’t forget to have fun!