Cut the roast in 4 pieces. I had two 1 1/2 pound roasts and cut them each in half. This helps keep the cooking time short. Place garlic and avocado oils in the instant pot and hit the "saute" button. Add the roast and sprinkle with the salt. Cook for 5 minutes, turning to brown on all sides.
Hit "cancel" and add in the fresh herbs and water. Place lid on, make sure the valve is closed, and hit the "manual" button. Increase the time to 40 minutes.
While the beef is cooking, chop the vegetables and place in a bowl to be added.
Once the beef is done, let naturally release pressure for 15 minutes. Hit "cancel", and release the pressure. Once the pin drops open and add the vegetables. Try to cover them with the liquid as best as possible.
Place the lid on, make sure the valve is closed, hit "manual" and reduce the time to 10 minutes. Once that is done, hit "cancel", release the pressure and remove lid. Take out the beef and veggies and place them in a large bowl or on a platter. Shred the beef if desired.
Add the cassava flour to the liquid that remains in the pot. Whisk until fully incorporated. Turn on the "saute" and stir until thickened. Pour over the meat and veggies and serve.