Mississippi Pot Roast Recipe Instant Pot Frozen: Pressure Cooked Pepperoncini Richness

I developed this method after too many weeknights of forgotten thawing left me scrambling for dinner solutions. The Instant Pot transforms a frozen chuck roast into fall-apart tender meat with minimal effort.

What sets this apart is the combination of ranch seasoning, au jus mix, and pepperoncini that create a tangy, rich sauce. The pressure cooker works its magic in under 90 minutes, infusing every bite with bold flavor.

The result is a restaurant-quality pot roast that’s juicy and packed with the signature Mississippi taste. The meat shreds effortlessly, soaking up every drop of the savory cooking liquid.

Serve over mashed potatoes or with crusty bread to mop up the sauce. This is the kind of meal that turns a busy evening into something special.

Ingredients for Mississippi Pot Roast Recipe Instant Pot Frozen

Frozen chuck, ranch mix, pepperoncini, and butter. That’s the whole magic trick.

The chuck roast is key here. Frozen solid works perfectly—no need to thaw, which is the whole point. Look for well-marbled pieces at Costco or Sam’s Club for the best value. I usually grab a 4-pound pack and freeze it in 2.5-pound portions specifically for this. The ranch and au jus mixes are non-negotiable for that signature Mississippi flavor (and yes, the brands matter).

No ranch packets? Make your own with 1 tbsp each dried dill, parsley, and onion flakes plus 1 tsp each garlic powder, onion powder, salt, and pepper. Out of au jus? Beef bouillon cube dissolved in 1 cup water plus a splash of soy sauce works. The pepperoncini juice is liquid gold—don’t drain it all. Any mild banana pepper works if you can’t find pepperoncini.

Leftovers keep 4-5 days in the fridge and freeze beautifully for 3 months. The flavor actually improves overnight. I portion extras into freezer bags with some of that amazing sauce—perfect for quick sandwiches or tacos later.

Step-by-Step Instructions for Mississippi Pot Roast Instant Pot Frozen

Here’s the method. Straightforward, tested, works every time.

Step 1: Layer the Frozen Chuck Roast and Aromatics

Place the 2.5 lb Frozen Chuck Roast directly into the Instant Pot liner—no thawing required. Add the 1 whole Yellow Onion (quartered), 4 cloves Garlic Cloves (smashed, skin on), and 3 whole Carrots (peeled and cut into 2-inch chunks) around the roast.

This is the beauty of the Instant Pot—you can start with a frozen solid block of meat and still achieve tender results. The aromatics create a flavor base that infuses the roast as it cooks.

Step 2: Add Seasonings and Liquids

Sprinkle the 1 package Ranch Seasoning Mix, 1 package Au Jus Mix, 1 tsp Kosher Salt, and 0.5 tsp Black Pepper evenly over the roast. Pour in the 1 cup Beef Broth and 1 tbsp Worcestershire Sauce around the meat, not directly on top.

Place the 0.5 cup Unsalted Butter (cut into slices) on top of the roast. The butter will melt as the pot heats, basting the meat with rich flavor. Add the 8 pieces Pepperoncini Peppers and their reserved ¼ cup juices for that signature tangy kick.

Step 3: Pressure Cook to Tender Perfection

Secure the Instant Pot lid, set the valve to sealing, and cook on high pressure for 90 minutes. The pot will take about 15-20 minutes to come to pressure before the timer starts.

Once the cooking time is complete, allow the pressure to release naturally for 15 minutes before switching the valve to venting. This natural release prevents the roast from seizing up and ensures it stays moist and tender.

Step 4: Shred and Serve

Carefully remove the frozen chuck roast from the Instant Pot and place it on a cutting board. Using two forks, shred the meat—it should pull apart effortlessly. The roast is done when it reaches an internal temperature of 195-200°F and shreds easily.

Return the shredded meat to the pot and stir it into the cooking liquid. This soaks up all the incredible flavors from the pepperoncini, ranch, and au jus. Taste and adjust seasoning with more kosher salt or black pepper if needed.

Serve hot with the carrots and onions from the pot, or over mashed potatoes or egg noodles to soak up the delicious sauce.

Essential Equipment for This Recipe

Instant Pot Essentials

You’ll need a 6-quart or larger Instant Pot—I use my Instant Pot Duo 7-in-1 for this. The larger capacity ensures proper pressure buildup with a 2.5 lb roast. A tight-sealing lid and functional pressure valve are non-negotiable for safety and results. 🔥

Prep Tools

A good chefs knife helps with chopping the onion and carrots quickly. I keep my Wüsthof 8-inch within reach. A cutting board with a groove to catch juices prevents messes when prepping the aromatics.

Release Valve Trick

Use a long wooden spoon to flip the release valve from sealing to venting. This keeps your hands safe from the hot steam. I learned this the hard way after a close call with my first Instant Pot meal.

Serving Supplies

Have tongs and two forks ready for shredding the meat. A slotted spoon is perfect for fishing out the pepperoncini peppers and veggies. I also set out a large serving bowl to mix everything together.

Optional Upgrades

A second inner pot is handy for prepping the next meal while the roast rests. I picked mine up at New Seasons Market for under $20. For easier cleanup, parchment paper slings help lift the roast out without scratching the pot. 💡

Safety First

Always check that the silicone ring is properly seated and the float valve is clean. I keep a small brush in my drawer for cleaning the valve after each use. Never force the lid open until all pressure has fully released.

Frequently Asked Questions