Remember those classic diners where they served the most incredible hot beef sandwiches? The kind where the roast was so tender it fell apart, piled high on soft bread and smothered in rich gravy, always with a side of creamy mashed potatoes? As a busy parent, I craved that comforting, nostalgic meal but knew I didn’t have 8 hours to babysit a slow cooker. My mission was clear: recreate that diner magic in a fraction of the time without sacrificing an ounce of flavor. Enter the Instant Pot. This genius recipe lets you cook the unbelievably tender beef roast and fluffy mashed potatoes at the same time, in the same pot. In just over an hour, you can have a complete, hearty, and soul satisfying meal on the table that tastes like it simmered all day. It’s my ultimate weeknight lifesaver and a guaranteed family favorite.
The flavor here is pure, classic comfort. The beef chuck roast transforms under pressure into incredibly savory, melt in your mouth strands, deeply seasoned with garlic and bathed in a rich, beefy broth. That broth becomes a luxuriously thick, savory gravy that’s the star of the show. The mashed potatoes are the perfect creamy, buttery counterpart; fluffy, smooth, and tangy with a hint of garlic and sour cream. When you assemble the sandwich, stacking the tender beef on soft bread, topping it with potatoes, and drenching everything in that glorious gravy, you get the ultimate textural experience: soft, juicy, creamy, and rich in every single bite. It’s hearty, satisfying, and tastes like a hug on a plate.
Expert Tips & Tricks for Instant Pot Success
- Pat the Roast Dry: Before seasoning, always pat the chuck roast completely dry with paper towels. This ensures a better sear (if you choose to) and allows the seasoning to stick properly. Moisture on the surface creates steam, which can dilute flavors.
- The Natural Release for Potatoes is Key: After pressure cooking the potatoes, let the pressure release naturally for a full 15 minutes. This allows the potatoes to finish cooking gently and evenly, preventing them from becoming waterlogged or gummy. A quick release can make them gluey.
- Thicken Gravy to Your Liking: The gravy packet will create a good sauce, but for a thicker, diner style gravy, use a cornstarch slurry. Mix 1 tablespoon of cornstarch with 1 tablespoon of cold water until smooth, then whisk it into the simmering broth. It will thicken almost instantly; add more for a thicker gravy.
Make Ahead, Storage & Freezing
- Meal Prep Dream: You can cook and shred the beef, make the mashed potatoes, and prepare the gravy up to 3 days in advance. Store components separately in airtight containers in the refrigerator. Reheat gently on the stovetop or in the microwave, adding a splash of broth to the beef and gravy if they’ve thickened.
- Storage & Reheating: Store assembled leftovers (beef, potatoes, and gravy mixed or separate) in the fridge for up to 4 days. Reheat individual portions in the microwave, or reheat beef and gravy together in a saucepan over low heat. Mashed potatoes reheat best with a splash of milk.
- Freezing Instructions: This dish is an excellent candidate for freezing! Freeze the shredded beef and gravy together in a freezer safe container for up to 3 months. Mashed potatoes can also be frozen, though their texture may be slightly less creamy upon thawing. Thaw overnight in the fridge before reheating.
Step by Step Instructions
1Season & Pressure Cook the Beef: Pat the 3 lb beef chuck roast dry. Season it on all sides with 1 tsp kosher salt and 1 tsp garlic powder. Pour 1 cup of beef broth into the inner pot of your Instant Pot. Place the seasoned roast in the pot. Secure the lid, set the valve to SEALING, and select MANUAL/PRESSURE COOK on HIGH pressure for 70 minutes.
2Quick Release & Add Potatoes: When the cook time is complete, perform a quick pressure release by carefully turning the valve to VENTING. Open the lid. Place a steamer basket (or just add them directly) into the pot on top of the beef. Add the 3 lbs of peeled and cubed Russet potatoes into the basket.
3Cook the Potatoes: Secure the lid again, valve to SEALING. Select MANUAL/PRESSURE COOK on HIGH pressure for 8 minutes. When the timer beeps, let the pressure release NATURALLY for 15 minutes, then turn the valve to vent any remaining pressure.
4Mash the Potatoes: Carefully remove the steamer basket and dump the cooked potatoes into a large mixing bowl. Add 3/4 cup milk, 3 Tbsp butter, 1 1/2 tsp kosher salt, 1/2 tsp garlic powder, and 1/4 cup sour cream. Mash with a potato masher or use a hand mixer until smooth and creamy. Cover to keep warm.
5Rest Beef & Make Gravy: Transfer the beef roast to a cutting board and let it rest. Carefully pour the hot broth from the Instant Pot through a fat separator (or skim the fat with a spoon). Return the defatted broth to the pot. Turn the Instant Pot to the SAUTÉ function (Normal). Slowly whisk in the packet of brown gravy mix. Let it simmer for 2-3 minutes until thickened. For a thicker gravy, whisk in a cornstarch slurry (1 Tbsp cornstarch + 1 Tbsp cold water).
6Shred & Assemble: Use two forks to shred the rested beef, discarding any large pieces of fat. Toast 12 slices of bread if desired. For each sandwich, place a generous pile of shredded beef on one slice of bread, top with another slice, and place a scoop of mashed potatoes on the side. Ladle the hot gravy generously over the entire sandwich and potatoes. Serve immediately.
Ingredient Substitutions
- Gluten Free: Use a certified gluten free brown gravy mix (like McCormick) and ensure your beef broth is gluten free. Serve the sandwich on gluten free bread or over the mashed potatoes as an “open face” bowl.
- Dairy Modifications: For the mashed potatoes, substitute the milk, butter, and sour cream with your favorite unsweetened dairy free alternatives (e.g., almond milk, vegan butter, and plain dairy free yogurt or sour cream).
- For the Beef: Chuck roast is ideal for shredding. A bottom round roast or rump roast will also work but may be slightly less tender. Avoid very lean cuts like sirloin.
- No Gravy Packet? Make a simple gravy with 2 cups of the defatted broth, 2 tablespoons of cornstarch mixed with 1/4 cup cold water, and season with salt, pepper, and a dash of Worcestershire sauce. Whisk over SAUTÉ until thick.
Serving Suggestions
This is a complete meal, but a simple side salad with a bright vinaigrette or some steamed green beans or roasted carrots can add a fresh, crisp element to balance the richness. For a fun twist, skip the second slice of bread and serve it as an open faced sandwich. The perfect beverage pairing is an ice cold lager or brown ale, a bold red wine like Cabernet Sauvignon or Malbec, or a classic root beer float for a truly nostalgic touch.
Frequently Asked Questions
- Q: Can I make this in a slow cooker instead?
- A: Absolutely! See the “Notes” section in the recipe card for full slow cooker instructions. Cook the beef on LOW for 6 hours, add potatoes for another 2-4 hours, then proceed with shredding and making gravy on the stovetop.
- Q: Do I have to sear the beef first?
- A: The recipe doesn’t require it for simplicity, but I highly recommend it for deeper flavor. Use the SAUTÉ function to sear the roast on all sides in a little oil before adding the broth and pressure cooking.
- Q: My gravy is too thin/thick. How can I fix it?
- A: For thin gravy, create a slurry with more cornstarch (1 Tbsp at a time). For gravy that’s too thick, simply whisk in a little extra beef broth or water until it reaches your desired consistency.
Recommended Equipment
- 6 Quart or 8 Quart Instant Pot (or other electric pressure cooker): The essential multi cooker for this one pot meal.
- Steamer Basket with Handles: Makes removing the hot potatoes a breeze and keeps them from sitting directly in the broth. A simple trivet can also work.
- Fat Separator or Large Heatproof Measuring Cup: The easiest way to separate the rich cooking liquid from the rendered fat for a smooth, non greasy gravy.
- Potato Masher or Hand Mixer: For creating perfectly smooth and creamy mashed potatoes.
Instant Pot Hot Beef Sandwich & Mashed Potatoes
Ingredients
For the Roast Beef:
- 3 lbs beef chuck roast trimmed
- 1 tsp kosher salt
- 1 tsp garlic powder
- 1 cup beef broth
- 1 packet 0.87 oz brown gravy mix
For the Mashed Potatoes:
- 3 lbs Russet potatoes peeled and cut into 2 inch chunks
- 1 1/2 tsp kosher salt
- 3/4 cup milk whole or 2%
- 3 Tbsp unsalted butter
- 1/2 tsp garlic powder
- 1/4 cup sour cream
For Assembly:
- 12 slices soft white bread Texas toast, or hoagie rolls
Instructions
- Cook the Beef: Season the chuck roast with 1 tsp salt and 1 tsp garlic powder. Pour beef broth into the Instant Pot and place the roast inside. Lock the lid, set the valve to Sealing, and select Manual/Pressure Cook on High Pressure for 70 minutes. When done, perform a Quick Release.
- Cook the Potatoes: Open the pot. Place a steamer basket (or trivet) over the beef and add the potato chunks. Lock the lid again, valve to Sealing. Cook on High Pressure for 8 minutes. When the timer beeps, let the pressure release Naturally for 15 minutes, then release any remaining pressure.
- Mash Potatoes: Carefully remove the steamer basket. Transfer potatoes to a large bowl. Add the milk, butter, 1 1/2 tsp salt, 1/2 tsp garlic powder, and sour cream. Mash until smooth and creamy. Cover to keep warm.
- Make Gravy & Shred Beef: Transfer the beef to a cutting board to rest. Carefully pour the broth from the pot through a fat separator. Return the defatted broth to the pot. Select the Sauté function (Normal). Whisk in the gravy packet until thickened, 2-3 minutes. For thicker gravy, whisk in a slurry of 1 Tbsp cornstarch + 1 Tbsp cold water.
- Shred the beef with two forks, discarding any large fat pieces.
- Assemble: Toast bread if desired. For each sandwich, pile shredded beef on one slice, top with another slice, and add a scoop of mashed potatoes on the side. Generously ladle hot gravy over everything. Serve immediately.
