Koji Beef Jus Recipe

In a large Dutch oven, heat oil over high heat until lightly smoking. Add beef shins or oxtail, and cook, flipping and stirring pieces occasionally, until well browned on all sides, 12 to 15 minutes. Using tongs, transfer beef to a large plate, and set aside. Reduce heat to medium-high.

Add carrot, celery, and onion to now-empty pot and cook, stirring occasionally, until starting to lightly brown, about 8 minutes. Add wine, bay leaves, thyme, and parsley and cook, scraping up browned bits from bottom of pot. Bring to a boil over high heat and cook until reduced by half, about 10 minutes.

Add stock and return beef to the pot. Bring to a boil, and then reduce to a light simmer. Simmer, stirring occasionally, until beef is just tender and liquid is reduced by half, about 1 hour.

Using tongs, transfer beef to a medium saucepan. Pour remaining contents of pot through a fine-mesh strainer into saucepan. Discard strained vegetables and aromatics.

Using a ladle, skim excess fat off top of liquid and discard. Bring to a boil, reduce heat to a light simmer, and cook until beef is completely tender and liquid is reduced to about 2 cups (475ml), about 45 minutes. Transfer beef to a serving plate and tent with foil to keep warm or set aside for another use. Stir in shio koji and taste for seasoning, adjusting with salt and pepper if desired (jus shouldn't need additional salt). Keep warm, until ready to serve with koji prime rib .