Slow Cooker Pork Tenderloin: Juicy Garlic Herb Recipe

Pork tenderloin is lean and cooks fast, which is why so many slow cooker versions come out gray and stringy. This slow cooker pork tenderloin gets a smoked paprika and thyme rub, sits on a bed of onion and smashed garlic, and comes out at 145°F with juicy, blush-pink slices and a quick garlic herb pan sauce. If you shop in the UK or Australia, it's the same cut you know as pork fillet.

Why You'll Love This Slow Cooker Pork Tenderloin

• Ten minutes of hands-on work. Pat, rub, layer and walk away. The optional sear adds about five more.
• It stays juicy. You pull it at 145°F instead of cooking by the clock, so the slices are moist and tender, not chalky.
• The sauce mostly makes itself. Broth, Dijon and cider vinegar mingle with the pork juices, then a quick simmer finishes it.
• Good leftovers. Six servings means thin cold slices for sandwiches the next day.

Ingredients

Pork and rub

• 2 pork tenderloins (about 1 lb / 450 g each, 2 lb / 900 g total), silver skin trimmed
• 1 tbsp olive oil
• 1 tsp smoked paprika
• 1 tsp garlic powder
• 1 tsp dried thyme
• 3/4 tsp kosher salt (about 4 g)
• 1/2 tsp black pepper

Slow cooker base

• 1 medium yellow onion, sliced
• 4 garlic cloves, smashed
• 1/2 cup (120 ml) low-sodium chicken broth
• 1 tbsp Dijon mustard
• 1 tbsp apple cider vinegar

Sauce and finish

• 2 tsp cornstarch mixed with 1 tbsp cold water (optional, to thicken the sauce)
• Chopped fresh parsley to finish

Only have table salt? Use about half as much. The fine grains pack tighter, so a full 3/4 tsp tastes much saltier.

How to Make Garlic Herb Pork in the Slow Cooker

1. Prep the pork. Pat the tenderloins dry with paper towels. Slide a thin knife under the silver skin, the shiny, pale membrane on the surface, tilt the blade up slightly and trim it away in strips. The pork should be fully thawed before you start.
2. Season it. Rub the tenderloins all over with the olive oil, then the smoked paprika, garlic powder, dried thyme, salt and pepper. Dry meat holds the rub better, which is why the paper towels matter.
3. Sear (optional). For more color, sear the tenderloins in a hot skillet for about 2 minutes per side, until the rub turns deep brown and smells toasty. This step is optional. Skip it and the pork is still juicy, just paler.
4. Build the base. Scatter the sliced onion and smashed garlic over the bottom of the slow cooker. They keep the pork off the floor of the pot and slowly melt into the sauce.
5. Add the pork. Lay the tenderloins side by side on the onions without crowding them. If your cooker is narrow, cut each one in half rather than stacking them.
6. Pour in the liquid. Stir the broth, Dijon mustard and apple cider vinegar together, then pour it around the pork, not over it, so the rub stays on the meat.
7. Cook with the lid on. Cover and cook on low for about 3 hours or on high for 1 1/2 to 2 hours. Start checking the temperature at 2 1/2 hours on low (1 1/4 hours on high), because slow cookers vary a lot.
8. Check the temperature. Push an instant-read thermometer into the thickest part of each tenderloin. Take the pork out when it reads 145°F (63°C). The center will look faintly pink, and that's what you want.
9. Rest. Move the pork to a cutting board and rest it for 5 minutes. The USDA safe minimum for pork is 145°F followed by a 3-minute rest, so 5 minutes covers it and gives the juices time to settle.
10. Make the sauce. Pour the juices, onion and garlic from the slow cooker into a small saucepan and simmer for 3 to 4 minutes. If you want it thicker, whisk in the cornstarch slurry and let it bubble for another minute until it coats a spoon.
11. Slice and serve. Cut the pork into 1/2-inch rounds, spoon the sauce over and finish with chopped parsley. Don't hold the cooked pork on the warm setting for hours, and refrigerate leftovers within 2 hours.

Tips for Juicy, Tender Pork

Use a thermometer, not the clock. Tenderloin has almost no fat or connective tissue to protect it, so a few minutes past 145°F takes it from juicy to dry. Slow cookers also run hot or cool depending on the model and how full they are. Treat 3 hours as a guide and let the thermometer decide.

Trim the silver skin. That thin membrane doesn't break down at slow cooker temperatures. Leave it on and you get a chewy strip on every slice.

Go easy on the liquid. Half a cup is plenty. The pork and onion release their own juices, and extra broth just thins out the sauce.

Keep the lid on. Every peek lets heat escape, and the cooker takes a while to climb back up. Wait for the first temperature check.

Never cook it from frozen. A frozen tenderloin warms too slowly and spends too long at unsafe temperatures. Thaw it in the fridge overnight.

Skip the warm setting. Tenderloin keeps cooking on warm, and after an hour or two it's dry. Slice it as soon as it has rested.

Tenderloin and pork loin aren't the same. Loin is a wider roast, often 2 to 4 lb, and needs more time. Tenderloin is long, narrow and about 1 lb. If you use a loin roast, add time and go by the 145°F reading.

Sear when you can. It's optional, but browning the rub adds flavor the slow cooker can't.

Same onion and garlic trick, different protein: our garlic herb slow cooker chicken thighs are just as hands-off.

Variations: 3 Easy Flavor Twists

Same method, same 145°F check. Only the flavors change.

Apple cider and sage

Swap the broth for 1/2 cup (120 ml) apple cider, use 1 tsp dried sage instead of the thyme, and tuck 1 sliced apple in with the onions. Keep the Dijon. It cuts the sweetness.

Honey Dijon

Bump the Dijon up to 2 tbsp and stir 2 tbsp honey into the broth. Leave out the smoked paprika for a cleaner mustard flavor. When you simmer the juices, they turn glossy and sticky.

BBQ

Replace the broth, Dijon and vinegar with 1/2 cup (120 ml) BBQ sauce thinned with 2 tbsp water. Keep the rub. Pour the sauce around the pork, since sugary sauce can scorch where it touches the hot sides.

What to Serve with Garlic Herb Pork

That garlicky Dijon sauce needs something to soak into. Mashed potatoes are the obvious pick, and buttered egg noodles or plain white rice work just as well.

For something green, roast green beans at 425°F for about 15 minutes, or steam them and toss with butter and lemon. Honey-glazed carrots or a crunchy apple slaw bring a little sweetness, and pork always likes that.

Storage and Make-Ahead

Fridge: Refrigerate leftovers within 2 hours of cooking. Keep the slices in their sauce in an airtight container for up to 3 to 4 days. The sauce stops them drying out.

Freezer: Freeze the pork in its sauce for up to 2 to 3 months, then thaw overnight in the fridge.

Reheating: Warm the slices in a covered skillet with a splash of broth until they reach 165°F (74°C). Thin slices reheat more evenly than a whole chunk.

Make-ahead: Trim and rub the tenderloins up to a day ahead and keep them wrapped in the fridge. Just don't leave the cooked pork on warm all afternoon.

Frequently Asked Questions

Is pork fillet the same as pork tenderloin?

Yes. Pork fillet is the UK and Australian name for the same cut Americans call pork tenderloin, the long, narrow muscle along the backbone. Don't confuse it with pork loin, which is a bigger, wider cut that needs more cooking time.

Can I cook pork tenderloin from frozen in a slow cooker?

No. Frozen pork warms too slowly in a slow cooker and can sit for hours at temperatures where bacteria multiply. Thaw it fully in the fridge, cook it to 145°F (63°C) and rest it for 3 minutes before slicing. Once it's done, don't leave it on warm for hours.

Can I use pork loin instead?

You can, but it's a thicker cut, so it needs more time. Start checking around 3 hours on low and keep going until the center reads 145°F (63°C). The rub and sauce stay the same.

Why is my pork tenderloin dry, and should I use low or high?

Dry tenderloin almost always went past 145°F, sat on warm, or simmered in too much liquid. Low is more forgiving because the temperature climbs slowly and gives you a wider window. High works when you're short on time, but start checking at 1 1/4 hours.

How do I thicken the sauce?

Simmer the cooking juices in a small saucepan for 3 to 4 minutes. Whisk 2 tsp cornstarch with 1 tbsp cold water, stir it in and let it bubble for a minute until it coats a spoon.

Ten minutes of prep, one thermometer, and dinner mostly takes care of itself.