PREPARING THE STOCK POT
Preheat your oven to 425°F. Coat the Fullblood Wagyu beef bones with the tomato paste, & place them on a baking sheet pan. Rough chop the Spanish onions, celery ribs, and carrots. Toss together with olive oil, and season with salt and freshly ground black pepper. Place these ingredients on a second/separate baking sheet pan.Add the bay leaves, garlic, thyme, and black peppercorns to the second baking sheet pan (with the onions, celery, and carrots).

Bake both pans at 425°F for 35-45 minutes or until caramelized. Drain the excess fat off the cooked beef bones tray, and discard the excess fat. Place the bones in the stock pot. Place the roasted vegetables in the stock pot as well. Making sure there is no oil on the tray (that the beef bones were cooked on). Then, place the pan on the stove top di-rectly over a burner on low heat. Add 1/2 cup of water to the tray, and scrape all the browned bits off the tray.

Add these browned bits to the stock pot. Then, add one gallon of water to the stock pot.

FINAL STEPS
Place the stock pot on the stove over medium-low heat. Please note: You do NOT want to let the stock pot come to a boil. Just under a simmer, let everything continue to cook for 5-6 hours. Then, remove the stock pot from the stove. Place the beef stock through a fine mesh strainer, and discard the remaining vegetables and bones. Let the stock sit a room temperature for 30 minutes to allow the fat to rise to the top.

Skim off the fat using a small ladle and discard the fat (or save it for a different use). Place the Fullblood Wagyu beef stock in glass canning jars with lids, and store in the refrigerator for up to 14 days.