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This 4-ingredient Slow Cooker pork tenderloin is tender, sliceable, and covered in creamy onion-mushroom gravy. There’s no browning, no extra pan, and no complicated prep—just add everything to the Slow Cooker and let it do the work. You’re going to love it over mashed potatoes, egg noodles, or rice.
Why You’ll Love It
- Just 4 ingredients — pork tenderloin, onion soup mix, cream of mushroom soup, and water.
- No browning required — everything goes straight into the Slow Cooker.
- Tender, sliceable pork — a whole tenderloin cooks in a reasonable amount of time without drying out.
- Cozy creamy gravy — the onion-mushroom sauce is perfect over potatoes, noodles, or rice.
- Great leftovers — the pork is delicious in Sandwiches or quesadillas.
Ingredient Notes
Pork tenderloin is not the same thing as pork loin. They are both pork, yes, but they cook differently, and the tenderloin is the long, narrow, tender cut you want here. Look for one that weighs about 1 to 1 1/2 pounds. Trim off any obvious silver skin if your package hasn’t already had it removed. It’s that tough, shiny little membrane that does not improve with age, unlike some of us.
For the onion soup mix, I use the regular dry packet—Lipton is the one I usually grab because that’s what every grocery store around here carries. Use the full 1-ounce packet. It gives the gravy most of its seasoning, so don’t add extra salt right off the bat. I made that mistake once and the gravy was very salty.
Condensed cream of mushroom soup makes the gravy creamy and old-fashioned in the best possible way. I am not going to pretend homemade mushroom sauce is the same level of effort. It isn’t. Use the can. If mushrooms are a hard no in your household, cream of celery works nicely too, though then it’s a different flavor—not worse, just different.
The water thins the soup enough to make a sauce as the pork cooks. You can use beef broth instead if you want a deeper, richer taste, but plain water is what I use most of the time because it’s sitting right there in the faucet, and I’m nothing if not practical when I’m tired.
Ingredients
- 1 whole pork tenderloin, about 1 to 1 1/2 pounds, trimmed of excess silver skin
- 1 packet (1 ounce) dry onion soup mix
- 1 can (10.5 ounces) condensed cream of mushroom soup
- 1/2 cup water
Instructions
Place the whole pork tenderloin in the bottom of your slow cooker. Leave it in one long piece—no cutting it up, no browning it first, no extra pan to wash later. Keep the pork refrigerated until you’re ready to start, and do give your hands, knife, and cutting board a good hot-soapy wash afterward. Raw meat cleanup is boring, but so is spending a weekend feeling lousy.
In a medium bowl, whisk together the dry onion soup mix, condensed cream of mushroom soup, and 1/2 cup water until it is mostly smooth. It may look a little lumpy, and that is fine. Do not stand there chasing every tiny lump with the whisk like it has personally offended you; the slow cooker will sort it out.
Pour the onion-and-mushroom mixture evenly over the pork tenderloin, coating the top as best you can. Some sauce will slide down the sides and pool around the meat. That puddle is becoming gravy, which sounds much nicer than “puddle,” so let’s call it gravy-in-progress.
Cover the slow cooker and cook on LOW for 4 to 5 hours or on HIGH for 2 to 3 hours. Start checking near the earlier end if your slow cooker tends to run hot—mine does, although it insists it is innocent. The pork is done when it is very tender and reaches at least 145°F in the thickest part on an instant-read thermometer.
Transfer the cooked pork tenderloin to a cutting board and let it rest for about 5 minutes. While it rests, stir the sauce in the slow cooker well, bringing any separated juices back into the creamy gravy. It may not look glamorous in the crock, but it will still taste delicious.
Slice the pork into 1/2-inch-thick medallions and serve warm with plenty of the onion-mushroom gravy spooned over the top. Mashed potatoes are my first choice, but buttered egg noodles or rice will catch every bit of sauce, and that is really the mission here.
Variations
If I have beef broth open, I sometimes swap the 1/2 cup water for 1/2 cup beef broth. It makes the gravy darker and a little more robust, especially good over egg noodles. You can also stir 1 tablespoon Worcestershire sauce into the soup mixture for extra savory depth. It works well that way, though I’m not sure it’s necessary. See? Contradictory. Welcome to my kitchen.
For a lighter, more celery-forward sauce, use condensed cream of celery soup instead of cream of mushroom. It’s a nice option for anyone who prefers to skip mushrooms.
You can scatter one small sliced onion or about 1/2 cup sliced carrots around the pork before adding the sauce. They soften right into the gravy. I tried adding a bunch of baby potatoes once, thinking I’d make it a whole meal in one pot. They took forever, the pork got a little too done, and dinner was late. Not a disaster, but not my finest hour either. Keep the potatoes separate unless you enjoy gambling with dinner.
Storage & Reheating
Refrigerate leftover pork and gravy within 2 hours, ideally in a shallow container so it cools down properly. It will keep for 3 to 4 days in the refrigerator. I usually slice all the remaining pork before storing it because it makes lunches easier, though sometimes I leave a few pieces whole for easy cold pork with a fork. Leftovers are not always elegant.
To reheat, put the slices and gravy in a covered skillet or microwave-safe dish and warm until hot and steaming. Add a spoonful of water if the gravy has thickened too much in the fridge—it usually does. The microwave works fine. Cover it loosely so you don’t end up scrubbing gravy freckles off the inside of the microwave. Ask me how I know.
The leftover meat is particularly nice on soft sandwich rolls with yellow mustard or horseradish. Or make quesadillas with it, which sounds a little odd until you taste one.
Final Notes
There’s something comforting about a dinner like this—not fancy, not trendy, not trying to impress with smoked paprika foam or whatever is popular now. Just pork, gravy, and the smell of onions drifting through the house.
There should be mashed potatoes.
4-Ingredient Slow Cooker Savory Pork Tenderloin
Ingredients
- 1 whole pork tenderloin About 1 to 1 1/2 pounds, trimmed of excess silver skin
- 1 packet dry onion soup mix 1-ounce packet
- 1 can condensed cream of mushroom soup 10.5 ounces
- 1/2 cup water
Instructions
- Place the whole pork tenderloin in the bottom of your slow cooker, leaving it in one long piece without cutting or browning it first.
- In a medium bowl, whisk together the dry onion soup mix, condensed cream of mushroom soup, and water until mostly smooth.
- Pour the onion-and-mushroom mixture evenly over the pork tenderloin, coating the top and allowing the sauce to pool around the meat.
- Cover the slow cooker and cook on LOW for 4 to 5 hours or on HIGH for 2 to 3 hours, until the pork is very tender and reaches at least 145°F in the thickest part on an instant-read thermometer.
- Transfer the cooked pork tenderloin to a cutting board and let it rest for about 5 minutes while you stir the sauce in the slow cooker well.
- Slice the pork into 1/2-inch-thick medallions and serve warm with the onion-mushroom gravy spooned over the top.