Select Sauté and continue pressing to reach Sauté on High. Pour oil into steel inner pot.
Season chuck roast with salt and pepper, then sear in hot oil until browned on the two largest sides, 2 to 4 minutes per side. Remove chuck roast from pot and set aside.
Add butter to inner pot. Once melted, add onion and cook until soft and translucent, 2 to 3 minutes. Add onion powder, garlic powder, dried thyme, and dried parsley and continue stirring until fragrant, about 30 seconds.
Select Cancel to turn off Sauté.
Stir beef broth, pepperoncinis, pepperoncini juice, and bay leaves into pot. Nestle chuck roast down into the liquid.
Lock pressure cooker lid in place and set steam vent handle to Sealing. Select Pressure Cook (manual) on High and cook for 60 minutes. Let pressure release naturally.
Transfer chuck roast to a cutting board and shred with two forks. Return roast to inner pot to keep warm or serve immediately over mashed potatoes for a perfect meal!
