One-Skillet Mustard-Herb-Crusted Roast Pork Tenderloin and Root Vegetables is fancy enough for Sunday dinner—but it’s done in just about an hour, making it quick and easy enough for a weeknight! Here, I’ve paired a roast pork tenderloin slathered in an herby mustard crust with roasted shallots, carrots, potatoes, and fennel. The meal is roasted all in the same pan, so cleanup is a breeze!
The Frank family are meat-and-potatoes folk. Although most of the Franks are adventurous eaters who graciously (even eagerly!) indulge my culinary travels, one is definitely on the “picky eater” (P.E.) end of the spectrum. For our P.E., even soups containing stuff besides meat and broth (for example, vegetables and noodles) are an issue. Any recognizable vegetable matter—when mixed with something else—is RIGHT OUT (though our P.E. will suffer through the veggies separately—and I do mean suffer). Needless to say, mealtimes can be a bit of a struggle.
Meat-and-potatoes meals are a relief at times: they’re simple to prepare and give our P.E. a meal he can easily wrap his brain around. Last week was a bit of a fluke: I had gotten very busy and hadn’t done a very good job at planning meals for the week. I’d sent the hubster to the store with a disjointed shopping list and a vague idea that I’d make some kind of pasta that night. Phil gamely rounded up everything on my shopping list, but texted me when he got to the meat department. He wanted to know whether I’d be interested in pork tenderloins, which were on a raging sale.
“Yes, yes, YES!” I texted back. Smiley face, heart, blowing kiss.
I had new potatoes and baby carrots on hand, and an idea was taking shape in my mind: One-Skillet Mustard-Herb-Crusted Roast Pork Tenderloin with Root Vegetables. I sent the hubster back to the produce department for fennel and shallots to round it all out—bless his patient heart.
Prepping Mustard-Herb-Crusted Roast Pork Tenderloin with Root Vegetables
When Phil got home with the goodies, I set to work. First, I snipped some rosemary, thyme, and sage sprigs from the garden (ah, the pleasures of summertime and having garden veggies and herbs at my fingertips!). I chopped the rosemary and mixed it in with grainy Dijon mustard along with minced garlic, salt and pepper, and a teaspoon of my favorite Bavarian herb mix. Then I trimmed up the pork loin, removing the silver skin (a sheath of connective tissue, so named because of its silvery appearance) and removing excess fat.
I cut the pork into 2 sections: the skinny and thick parts of the loin. Not only does this make the searing easier (the pork tenderloin is quite long otherwise), but the thin part of the tenderloin will finish cooking before the thick part does: sectioning the tenderloin allows me to remove the “skinny” part and let it rest while the thick part finishes cooking—no overcooked, rubbery pork in this house!
I dried the two halves with paper towels, then seasoned with salt and pepper. While I heated some oil in my cast-iron skillet, I prepped the vegetables.
To make Mustard-Herb-Crusted Roast Pork Tenderloin a weeknight-possible meal, I needed the veggies to be done quickly. This takes some strategizing. The shallots and fennel are never an issue: I usually either leave the trimmed shallots whole or cut them in half. After I trimmed and cored the fennel, I cut it into ~3/4″ pieces. Carrots take quite some time to cook, so I sliced them about 1/3″ thick on the bias. I halved the new potatoes, which were about 1″ in diameter (I cut the longer ones into thirds). Then I tossed all the veggies with olive oil, salt and pepper, and herbs (I use a mix of dried and fresh).
Searing and roasting the Mustard-Herb-Crusted Roast Pork Tenderloin
I gave the pork tenderloin sections a quick sear on all sides in the hot pan, then set the sections aside while I deglaze with some chicken broth, add in the root vegetables, lid the skillet, and pop it into a 375º oven for 20 minutes (the veggies need a head start on the meat, which finishes very quickly in the oven). Meanwhile, I slathered the pork with the herby mustard mixture.
After 20 minutes, I removed the lid and added the meat. To monitor the meat’s temperature, I used one of those digital thermometers that connects to a digital readout through a long, metal cord. I put the probe right in the center of the thinnest section of the pork tenderloin. I set the alarm to 143º: when the skinny section reaches this temp, I pull it and remove the probe, which I stick into the thick section of the tenderloin and continue baking until it reaches 140º. The pork will not take long to cook: if I’m not using a digital thermometer, I start checking with an instant-read thermometer after 15 minutes (checking the thickest part of each tenderloin section).
You’re probably wondering about that target temperature, so let me ‘splain. The USDA now recommends cooking pork to 145º rather than the previously recommended, overdone-shoe-leather temperature of 165º. At this temperature, pork will still be faintly pink—but that’s good. During a 10 minute rest, the pork will reach its recommended internal temperature (I ensure this by wrapping with foil).
While the pork rests, you could make a pan sauce after removing the pork and vegetables. That’s a simple matter of deglazing the pan with wine, scraping up the bits of meat and vegetables, adding in a bit of stock, reducing, and then stirring in some butter or cream. If you want a thicker sauce, you can use a slurry of 1 tablespoon of cornstarch mixed well with 1 tablespoon of water: whisk that into the pan, bring the mixture to a light boil for a few seconds, then spoon it over your meat. YUM.
I like to slice the tenderloin into ~1/2″ pieces and serve on a platter with the vegetables arranged in the middle. Somehow, I managed not to get a picture of that. I guess that’s not too surprising: once the meat is sliced, it’s a free-for-all at this house. I hope your family enjoys this just as much! And there you have it: a one-skillet Mustard-Herb-Crusted Roast Pork Tenderloin
For more one-pot meal inspiration, check out my how-to article, Mastering Easy One-Pot Meal Recipes!
- 1 ~2-lb. pork tenderloin, also known as pork loin filet, trimmed
- 2 tbsp. vegetable oil
- 4 tbsp. grainy dijon mustard
- 3 cloves garlic, minced
- 1 tbsp. fresh rosemary leaves, stripped from the stem and minced
- 2 tsp. Bavarian herb mix
- 3 cups of baby potatoes, cleaned and cut into 1/2" pieces
- 4 carrots, peeled and sliced ~1/3" thick on the bias
- 3 large shallots, trimmed and cut into quarters
- 2 fennel bulbs, trimmed, cored, and cut into ~1/2" pieces
- 4 sprigs fresh rosemary
- 2 sprigs fresh thyme
- 4 fresh sage leaves
- 2 tbsp. extra virgin olive oil
- 1 cup chicken stock
- 1/2 tsp. salt
- 1/4 tsp. freshly ground black pepper
- For the optional pan sauce:
- 2 tbsp. finely minced shallots
- 1/2 cup white wine
- 1/2 cup chicken stock
- 1 tsp. cornstarch mixed with 1 tbsp. water (only if you want a slightly thicker sauce)
- 1 tbsp. butter or a splash of cream
Preheat oven to 375º. Rinse the pork tenderloin and dry well with paper toweling. If the roast (like most tenderloins) is tapered at one end, cut it into 2 sections (crosswise across the roast) to make 1 thin section and 1 thick section. Season generously with salt and pepper.
Heat a large cast-iron skillet over medium-high heat and add the vegetable oil. While the pan heats, mix the mustard, garlic, rosemary, and herb mix; set aside. Mix the root vegetables with the olive oil, salt, and pepper.
When the oil in the pan begins to shimmer, add the 2 sections of tenderloin. Sear on all sides until nicely browned, about 2 minutes per side. Remove meat from pan and set aside.
Pour the chicken broth into the pan and scrape briefly with a wooden spoon to loosen any browned bits. Add the root vegetable mixture to the skillet, scatter with the fresh herbs, cover, and place in the oven to roast for 20 minutes.
Meanwhile, rub the pork tenderloin sections with the mustard mixture. If you are using a digital thermometer, push the probe into the center of the thinner pork tenderloin section and set the alarm for 143º.
Carefully remove the lid from the skillet and stir the vegetables. Add the pork tenderloin sections and any accumulated juices; roast, uncovered, for ~15 minutes, or until the temperature of the thinner pork tenderloin section reads 143º on a digital or instant-read thermometer. Remove the probe (if you are using a digital thermometer) and push it into the center of the thicker pork tenderloin section. (Remove the thinner pork tenderloin section to a plate and cover with foil.)
Continue roasting the thicker pork tenderloin section until it reaches an internal temperature of 143º. Remove, cover with foil, and let rest for 10 minutes. Remove the vegetables to a serving platter, discarding the herb sprigs.
For the optional pan sauce: pour off excess drippings in skillet, leaving about a tbsp. of drippings in the skillet (don't wipe out the skillet). If there aren't enough drippings, add a small amount of olive oil to make up the difference. Set the skillet over medium heat and add the shallot; sauté until softened, stirring occasionally, about 4 minutes. Add the wine, scraping up browned bits with a wooden spoon. Simmer until liquid is reduced by about half. Raise heat to medium-high and add the chicken stock, simmering until liquid is reduced by half and occasionally swirling the pan. Add the cornstarch and water mixture (if using), re-stirring carefully. Simmer for 30 seconds or until thickened slightly. Reduce heat to medium-low. Add the butter; swirl skillet to melt and mix into the sauce. Season to taste with salt and pepper.
Slice both sections of tenderloin roast about 1/2" thick and arrange on a platter with the vegetables heaped in the middle. Serve, pouring the pan sauce (if using) over the meat.