Koji Beef Jus

Ingredients

• 1 tablespoon vegetable oil
• 2 pounds beef shins or oxtail
• 1 large carrot, peeled and roughly chopped
• 2 ribs celery, roughly chopped
• 1 large onion, peeled and roughly chopped
• 1 bottle dry red wine
• 2 bay leaves
• 4 sprigs fresh thyme
• 4 sprigs fresh parsley
• 1 quart homemade beef stock, homemade brown or white chicken stock, or store-bought low-sodium chicken stock
• 1/4 cup blended shio koji

Directions

1. Warm the oil in a large Dutch oven over high heat until it just begins to smoke. Add the beef shins or oxtail and brown the pieces thoroughly, turning and moving them now and then, 12 to 15 minutes. Lift the beef out with tongs, place it on a large plate, and set it aside. Lower the heat to medium-high.
2. Add the carrot, celery, and onion to the empty pot. Cook, stirring from time to time, until the vegetables begin to take on a little color, about 8 minutes. Pour in the wine, then add the bay leaves, thyme, and parsley, scraping the browned bits from the bottom as it cooks. Turn the heat to high, bring everything to a boil, and cook until the liquid has reduced by half, about 10 minutes.
3. Add the stock, then return the beef to the pot. Bring the mixture back to a boil, then lower the heat so it settles into a gentle simmer. Cook, stirring occasionally, until the beef is just tender and the liquid has cooked down by half, about 1 hour.
4. Use tongs to move the beef into a medium saucepan. Strain everything left in the pot through a fine-mesh strainer into that saucepan. Throw away the strained vegetables and aromatics.
5. Skim and discard the extra fat from the surface of the liquid with a ladle. Bring the liquid to a boil, lower the heat to a gentle simmer, and continue cooking until the beef is fully tender and the liquid has reduced to about 2 cups (475ml), about 45 minutes. Move the beef to a serving plate and cover it loosely with foil to stay warm, or reserve it for another use. Stir in the shio koji, then taste and adjust with salt and pepper if you like, though the jus should not need more salt. Hold warm until it is time to serve with koji prime rib.