Preheat your oven to 375 degrees F. Place bones on a roasting pan or baking sheet and roast for one hour or until nicely browned.
Place roasted bones in slow cooker. Add vegetables, vinegar, and 1-2 Tbsp. salt. Fill the slow cooker with water so that bones are covered as much as possible. You can also make your broth in an instant pot, or in a soup pot on your stovetop.
Cover and cook for 24-48 hours in your slow cooker Alternate methods: simmer for 6-12 hours in a soup pot on stovetop or pressure cook for 2-4 hours in your instant pot.
Remove the bones and veggies, and strain the broth through a sieve or cheesecloth.
Season to taste with salt.
Pour into glass jars and refrigerate for 3-5 days. Or freeze in freezer-safe containers for later use.
To serve: heat broth and drink. Add a rosemary sprig to your mug if desired. Or use broth in soup or as cooking liquid for rice and other grains.
