OPTIONAL ROAST: preheat the oven to 425ºF. Once preheated, place the bones on a baking sheet, lined with foil if desired. Drizzle with 1 tablespoon avocado oil or other high heat oil and sprinkle with 2 teaspoons kosher salt. Roast for 40-45 minutes, flipping halfway through until golden.
PRESSURE COOK: add the peppercorns, garlic, and bay leaves to a mesh bag or wrap in kitchen twine, this just makes it easier to fish out later. Then add the beef bones, 2 teaspoons salt, vinegar, mesh bag with ingredients, yellow onions and veggies you plan on using to the instant pot. Cover the bones with water to just below the max fill line. Place the lid, seal and set the timer on manual high pressure for 150 minutes. (2.5 hours)
RELEASE PRESSURE: Allow a natural release, this will take 20-30 minutes. After that, turn the steam release knob or flip the switch.
LET COOL: Allow the bone broth to cool for several minutes uncovered. Discard leftover bones. Then strain using a fine mesh strainer lined with cheesecloth. Pop into an airtight container or mason jars to store in the refrigerator to use later in the week, freezer safe pints, or freeze in ice cube trays.