Mushroom and onion butter meet pork tenderloin in the slow cooker — it’s like a culinary rom-com, but less dramatic and more delicious. You want a hands-off dinner that still looks like you tried.
That’s why the slow cooker is your secret weapon. But here’s the catch!
You get tender meat, a silky mushroom-onion butter sauce, and zero stress. This recipe is cozy, easy, and perfect for nights when you want to impress without sweating the small stuff.
Contents
Equipment: Must-haves
- Slow cooker
- Skillet (preferably cast iron)
- Sharp knife
- Cutting board
- Tongs
- Measuring spoon
Equipment: Nice-to-haves
- Meat thermometer
- Kitchen twine
- Slotted spoon
- Whisk
- Small bowl
Ingredients
- 1 pork tenderloin (about 1.5 lb), trimmed
- 8 oz mushroom, sliced (cremini or button work great)
- 1 medium onion, thinly sliced
- 3 tbsp butter
- 1 tbsp olive oil
- 2 cloves garlic, minced
- 1 tsp fresh thyme leaves (or 1/2 tsp dried thyme)
- 1 cup beef broth
- 1 tbsp Worcestershire sauce
- 1 bay leaf
- 1 tsp salt, plus more to taste
- 1/2 tsp black pepper, plus more to taste
- 1 tbsp cornstarch
- 2 tbsp cold water (for cornstarch slurry)
- Fresh parsley, chopped (for garnish, optional)
Instructions
- Pat the pork tenderloin dry and season all over with salt and pepper.
- If using kitchen twine, tie the tenderloin at intervals so it cooks evenly and looks adorable on the platter.
- Heat the skillet over medium-high heat and add the olive oil and part of the butter until it foams.
- Sear the pork on all sides until it develops a golden crust, then remove and set aside — get a satisfying sizzle going.
- Add the remaining butter to the skillet and reduce heat to medium.
- Sauté the onion until it begins to soften and turn translucent.
- Toss in the mushroom and cook until it releases moisture and starts to brown.
- Stir in the garlic and thyme and cook until fragrant; don’t let the garlic burn unless you enjoy charred surprises.
- Deglaze the skillet with a splash of beef broth, scraping up browned bits because those bits are flavor gold.
- Transfer the onion and mushroom mixture to the slow cooker and nestle the seared pork on top.
- Pour the remaining beef broth and Worcestershire sauce into the slow cooker and add the bay leaf.
- Cover and cook on low until the pork is tender and reaches safe temperature; check once toward the end with a meat thermometer.
- Remove the pork to a cutting board and let it rest so the juices calm down and stop splashing everywhere.
- Turn the slow cooker to high or pour the cooking liquid into the skillet and bring to a simmer for the sauce.
- Make a cornstarch slurry in a small bowl with cold water and whisk it into the simmering liquid to thicken the sauce to glossy perfection.
- Slice the rested pork crosswise, spoon the mushroom-onion butter sauce over it, and garnish with chopped parsley if you’re feeling fancy.
What Else You Should Know
Tip: Searing the pork first is worth the tiny extra step — it locks in flavor and gives the sauce a deeper color. Timing: Cook on low for a set-and-forget dinner; the pork will be tender without falling apart.
If you’re short on time, cook on high but check sooner. Gravy trick: Mash a few mushroom into the sauce before adding the slurry for extra body.
Variations: Swap beef broth for chicken broth if that’s what you have. Add a splash of dry white wine during deglazing for brightness.
Swap thyme for rosemary if you prefer a woodsy note. Serving suggestion: Serve sliced tenderloin over creamy mashed potato or buttered egg noodle so the sauce has something to cling to.
Add a simple green like steamed green bean for color and crispness. Storage: Refrigerate leftovers in an airtight container for up to three days, or freeze the sliced pork and sauce for up to three months.
Reheat gently in a skillet or low oven to avoid drying out the meat. Safety: Use a meat thermometer to confirm the pork reaches a safe internal temperature before serving.
Resting the meat after cooking keeps the juices inside where they belong. Final laugh: If anyone asks how long it took, say you ‘spent an hour making it’ and then quietly tell them the slow cooker did all the heavy lifting.
You’ve earned that humble brag.
