American
Mustard-Herb Slow Cooker Pork Tenderloin
Quick-seared pork tenderloin cooks gently over onions with mustard, thyme, and broth, then rests before slicing into a reduced savory gravy that stays balanced and bright.
6 servings · 25 minutes prep · 165 minutes cook
Ingredients
Pork and Aromatics
- 2 pounds pork tenderloin, usually 2 tenderloins; silver skin removed
- 1 1/2 teaspoons Diamond Crystal kosher salt
- 3/4 teaspoon black pepper
- 1 tablespoon olive oil
- 1 large yellow onion, sliced 1/2 inch thick
- 4 garlic cloves, thinly sliced
- 6 thyme sprigs
Mustard Gravy
- 1 cup low-sodium chicken broth
- 2 tablespoons Dijon mustard
- 1 tablespoon apple cider vinegar
- 1 tablespoon cornstarch
- 2 tablespoons whole milk
- 1 tablespoon cold unsalted butter
Directions
Sear the Pork
- Pat the pork tenderloins completely dry and season with the salt and pepper.
- Heat the oil in a skillet over medium-high until shimmering. Brown the pork for 5 to 7 minutes total, turning to color all sides. Transfer immediately; the centers should remain raw.
Build the Slow Cooker
- Spread the onion, garlic, and thyme in a 5- to 6-quart slow cooker. Whisk the broth, mustard, and vinegar and pour around the onions.
- Set the pork on top, cover, and cook on LOW for 1 1/2 hours without lifting the lid. Make one quick temperature check at the thickest point of each tenderloin and remove any piece that has reached 145°F (63°C). If a piece is below 130°F (54°C), re-cover and wait 30 minutes before checking again; if it is 130 to 144°F (54 to 62°C), re-cover and check after 15 minutes. Continue using those temperature-based intervals and remove each tenderloin at 145°F; do not hold it in the cooker after it reaches temperature.
Rest and Finish the Gravy
- Rest the pork loosely tented for 10 minutes. Discard the thyme and transfer the onion and cooking liquid to the skillet. Boil over medium-high for 5 to 8 minutes until reduced by about one-third.
- Whisk the cornstarch with the milk, then whisk into the sauce and simmer 1 minute until glossy. Remove from heat and swirl in the butter. Slice pork 1/2 inch thick across the grain and serve with gravy around the slices.
