Preheat the oven to 300 degrees Fahrenheit.
Season the roast by sprinkling it with salt and pepper. Place olive oil in a large skillet. Over medium-high heat sear the roast for about 2-3 minutes per side, just to get it slightly brown.
Place the roast in the roasting pan. Pour on the liquid from the pepperoncinis jar. Sprinkle on the au jus powder and ranch dressing powder.
Cut up the butter and place small chunks of it over the roast. Place the pepperoncinis and garlic on top. Place the lid on the roasting pan or cover it tightly with tin foil.
Bake for 2 ½hours. Check for doneness. If it is not easy to tear apart, continue cooking for another ½ hour.
Calories: 567kcal | Carbohydrates: 1g | Protein: 44g | Fat: 44g | Saturated Fat: 21g | Polyunsaturated Fat: 3g | Monounsaturated Fat: 19g | Trans Fat: 2g | Cholesterol: 197mg | Sodium: 332mg | Potassium: 779mg | Fiber: 1g | Sugar: 1g | Vitamin A: 531IU | Vitamin C: 7mg | Calcium: 44mg | Iron: 5mg