celery - as needed to reach 780g of vegetables (chopped)
bay leaf - 1
thyme - half a bunch (fresh)
parsley stalks - from half a bunch
peppercorns - 20
garlic - 1 (head, halved)
tomato puree - 3 tablespoons
water - as needed (cold, to cover)
Instructions
Prepare Bones: Drizzle beef bones with olive oil and roast in a preheated oven at 220°C (430°F) for 30 minutes, flip, and roast for another 30 minutes.
Prepare Vegetables: Combine halved onions, chopped carrots, and celery to make up 780g of vegetables. Add to a roasting tray with tomato puree.
Roast Vegetables: After removing bones, roast vegetables in the same oven until colored, about 20-25 minutes.
Combine and Cook: Place roasted bones in a large pot, cover with ice and cold water. Bring to a simmer, skimming off impurities for the first hour.
Add Vegetables and Aromatics: After 8 hours, add roasted vegetables. After 9 hours, add bay leaf, thyme, parsley stalks, peppercorns, and garlic. Turn off heat after 9.5 hours and let sit for 30 minutes.
Strain: Strain stock through a fine sieve or cheesecloth. Divide into clear and cloudy portions for different uses.