FOR THE JUS:
4 tbsp. canola oil
4 lbs. boneless veal breast, trimmed of fat,
cut into 1" cubes
1 yellow onion, roughly chopped
1 carrot, roughly chopped
1 head garlic, halved crosswise
4 sprigs thyme
FOR THE VEAL CHOP:
1 1 1/2-lb. bone-in veal chop,
about 2 1/2" thick
4 tbsp. extra-virgin olive oil
Kosher salt and freshly ground black pepper,
2 tbsp. unsalted butter
2 sprigs rosemary
4 sprigs thyme
2 cloves garlic
4 oz. shiitake mushrooms, stemmed
1. Make the jus: Heat 2 tbsp. oil in 6-qt. wide-bottomed pot. Working in 2 batches, add the veal and cook, stirring occasionally, until well browned, about 6 minutes. Using a slotted spoon, transfer veal to a plate.
2. Add onions, carrots, garlic, and thyme and cook, stirring occasionally, until browned. Add 1 cup water and stir vigorously to loosen browned bits from bottom of pot. Add veal and 16 cups water and bring to a boil. Reduce heat to medium-low and simmer, without stirring, until the broth has reduced to 8 cups, about 3 hours.
3. Strain liquid through a fine-mesh sieve into a 4-qt. saucepan set over high heat; reserve solids for stew or soup. Bring liquid to a boil over medium-high heat and cook until it reduces to about 1/2 cup, about 1 hour; cover and set sauce aside.
4. Heat oven to 350˚. Rub veal chop with 1 tbsp. oil and massage in salt and pepper. Heat 1 tbsp. oil in a 10" skillet over high heat. Add veal and cook, turning occasionally, until browned on all sides, about 12 minutes. Add butter, rosemary, thyme, and garlic to the skillet and transfer to the oven. Roast, basting frequently with the juices, until veal is medium rare and an instant-read thermometer inserted into center of the chop reads 140˚, about 30 minutes. Transfer veal to a plate and let rest for 10 minutes. Discard herbs, garlic, and all but 2 tbsp. oil from skillet.
5. Place the skillet over medium-high heat, add mushrooms, and cook, stirring occasionally, until golden brown, 5 minutes. Carve veal into 1/2"-thick slices and serve with sauce and mushrooms.