Instructions

• Select SAUTE on the Instant Pot and heat the oil until shimmering.
• Add the chuck roast pieces in a single layer and sear on all sides until browned, working in batches if needed so pieces do not overcrowd the pot. Remove the browned beef to a plate and set aside.
• Pour the 1/4 cup liquid from the pepperoncini jar and the 3/4 cup beef broth into the pot. Scrape the bottom to deglaze and loosen any browned bits.
• Return the beef to the pot. Sprinkle the ranch seasoning packet and the dry onion soup mix packet evenly over the beef. Add the 8–10 pepperoncini peppers. Gently stir to distribute the seasonings and peppers.
• Cut the butter into 2–3 pieces and arrange the pieces over the beef.
• Secure the lid and set the vent to SEALING. Select PRESSURE COOK/MANUAL on high pressure and set the time for 60 minutes. (The Instant Pot will take about 7–8 minutes to come to pressure.)
• When the cooking program finishes, let the pressure release naturally for 15 minutes, then carefully move the vent to VENTING to release any remaining steam. When the float valve drops, remove the lid.
• Carefully transfer the beef to a plate or cutting board and shred with two forks.
• In a small bowl, whisk the cornstarch and water together until smooth to make a slurry. Select SAUTE on the Instant Pot and stir the slurry into the cooking liquid. Cook, stirring, until the sauce thickens (about 1–2 minutes).
• Return the shredded beef to the pot and stir to coat it in the thickened sauce.
• Serve the Mississippi pot roast with mashed potatoes and extra sauce as desired.