Plug in the Instant Pot, add the avocado oil and set to the Saute mode. Add the onion and saute, stirring occasionally, until the onion has softened.
Scoot onions off to the side and place short ribs on the hot surface. Cook 3 minutes on each side, or until the short ribs have a nice sear on both sides.
Add the remaining ingredients except for the tapioca flour and tomato paste. Secure the lid on the Instant Pot and pressure cook on high 35 minutes. Once the Instant Pot has finished its course, allow it to go into the Keep Warm mode for 30 minutes. Remove the lid and transfer the meat to a plate.
If desired, make gravy out of the rib juices. To do so, press Saute on the Instant Pot and add the tapioca flour and tomato paste. Bring mixture to a full boil, stirring constantly. Cook 3 to 5 minutes, or until a thick gravy has formed. Taste gravy for flavor and add sea salt to taste.
Cut the top off a bulb of garlic and drizzle with olive oil. Wrap in foil and roast in the oven 40 minutes at 375 degrees F. Allow garlic to cool, then peel all of the cloves.
Chop the Yukon gold potatoes into thirds, add them to a pot, and fill with water. Bring to a full boil and cook 10 to 15 minutes, or until potatoes are very tender when poked with a fork. Drain the potatoes.
Add roasted garlic, cooked potatoes, ghee, coconut milk, and sea salt to a blender. Blend until desired consistency is achieved. Note: if you have a potato masher, you can mash everything together in the same pot you used to cook the potatoes.
Serve beef short ribs over roasted garlic mashed potatoes with gravy.