Add the oil and sear the beef in batches, cooking each side undisturbed until a deep brown crust forms.

Transfer the browned beef to a plate and cover lightly to keep warm while finishing the rest.

Add water to the pot and scrape the bottom thoroughly with a wooden spoon to remove any browned bits.

Stir in the diced onion and minced garlic and cook briefly until fragrant and slightly softened.

Pour in the beef broth, pepperoncini juice, and Worcestershire sauce, then stir to combine.

Add salt, pepper, red pepper flakes, ranch mix, and au jus mix, stirring until everything is well incorporated.

Turn off sauté mode and return the beef to the pot, layering it with butter slices and whole garlic cloves.

Add the whole pepperoncinis and bay leaves, ensuring everything is evenly distributed.

Close the lid, seal the valve, and cook on high pressure until the beef becomes very tender.

Allow the pressure to release naturally for a period before carefully releasing any remaining pressure.

Open the lid and switch back to sauté mode if you want to thicken the sauce.

Mix cornstarch with water until smooth, then stir it into the pot and let the sauce simmer until thickened.

Remove bay leaves and serve the roast hot with your favorite sides and extra sauce.