Turn your Instant Pot to “Sauté” mode and add the beef, turning to brown on all sides, approximately 7 minutes. Remove the chuck roast from pan and set aside.
Heat the oil and add the onions, garlic, and carrots. Sauté until fragrant, about 5 minutes. Return the roast to the pot and add the beef broth, potatoes, button mushrooms, bay leaf, and fresh thyme. Press the “Pressure Cook” button and adjust time to 70 minutes.
When the timer beeps, you can perform a quick release by moving the pressure release to “Venting,” or you can let the pressure release naturally. A natural pressure release can take from 5 to 30 minutes. When the pressure is fully released, the float valve will drop and the lid will unlock and open.
Remove the meat and let it rest. Slice and serve with vegetables on a platter.