Step 1

Preheat oven to 450˚F (232˚C) with a large oven-safe pan on the middle rack. A large cast iron or braiser pan works well!

Step 2

Combine the rub ingredients in a small bowl and stir well to combine. Make sure there are any little lumps of baking soda.

Step 3

Place the tenderloins on a cutting board or a large sheet of plastic wrap, parchment paper, or butcher paper. Trim the silver skin from each tenderloin (that’s the tough white part - see the post for a link to a video demonstrating how to trim the silver skin). Pat them dry with a paper towel and drizzle each one lightly with olive oil.

Step 4

Sprinkle the rub over the tenderloins and pat it in to completely coat.

Step 5

When the oven has been preheated, carefully remove the hot pan and add 1½ tablespoons of olive oil. Swirl the pan to coat it with the oil.

Step 6

Lay the two tenderloins in the pan, smooth side down and reduce the temperature to 425˚F (218˚C). Return the pan to the oven for 8 minutes.

Step 7

After the 8 minutes, remove the pan from the oven and flip the tenderloins to the opposite side. Top each tenderloin with half of the butter pieces. Add the rosemary sprigs to the pan.

Step 8

Return the pan to the oven for 5 minutes then remove from the oven and baste the tenderloins with the pan juices. Check the temperature with an instant thermometer. (I like to insert the thermometer from the side into the center of the thickest part of the tenderloin.) You’re looking for an internal temp of 145˚F. If you’re not near 145, return to the oven for another 5 minutes. If you’re getting close (upper 130s or 140), return to the oven for 3 minutes.)

Step 9

Continue roasting and basting every 3-5 minutes until the tenderloins reach an internal temperature of This will take varying times, depending on the size of your tenderloins. (Go by the internal temperature, not the time.)

Step 10

Remove the tenderloins to a cutting board and tent with foil for 8-10 minutes.

Step 11

While the pork is resting, combine the chicken broth and cornstarch in a small bowl or measuring cup. Stir well to incorporate the cornstarch.

Step 12

Place the pan on the stovetop over medium-high heat. Pour the chicken broth mixture into the pan. Add the mustard (if using). Use a metal spoon or sturdy, heat-resistant spatula to stir the mixture, scraping the pan to remove the brown fond from the bottom (this has tons of great flavor!).

Step 13

Bring to a boil and cook for 1 minute, stirring continuously. Discard the rosemary sprigs. Add any accumulated juices from the tenderloins to the pan sauce.

Step 14

Slice the tenderloin into ½-1-inch slices. Transfer to a serving platter and drizzle with the sauce or serve the sauce on the side.

Step 15

We love this pork with roasted sweet potatoes or on top of mashed potatoes, drizzled with the yummy sauce and served with a simple green salad.

Step 16

I like to slice any leftovers thinly and use it to make toasted sandwiches layered with cheese on focaccia or artisan bread. Delicious!