- Preheat the oven to 400°F. Place bones on a parchment-lined, rimmed baking sheet along with onion, garlic, and carrots. Roast for 45 minutes: this will help give the broth added depth of flavor.
- Transfer bones and vegetables to a large pot. Add cold water to fully submerge all ingredients, about 12 cups. Add bay leaves, cover with the lid slightly ajar, and bring to a very low simmer.
- Let simmer for 12-24 hours, skimming any excess fat off occasionally. The bone broth is ready when it's caramel in color and flavorful.
- Using a mesh sieve, strain liquid to remove solids.
- Salt and pepper to taste, and store in airtight containers.
- This bone broth can be stored for 5 days in the fridge or up to 6 months in the freezer.