Heat olive oil in a large straight-sided skillet over high heat.

Season pork tenderloins with coarse salt and fresh ground pepper.

Cook pork until browned on all sides, approximately 5-6 minutes.

Reduce heat to medium-low.

Cover the skillet and cook, turning pork occasionally, until an instant-read thermometer inserted into the centers registers 150F, about 20-25 minutes.

Transfer pork to a plate and cover with foil. Reserve the skillet with juices.

Let the pork rest for 10 minutes.

Add whole-grain mustard and Dijon mustard to the skillet along with sour cream and any accumulated pork juices from the plate.

Whisk the mixture over medium heat until heated through, being careful not to boil.

If the sauce is too thick, add water to reach desired consistency.

Slice the pork and serve with the prepared pan sauce.

In a blender, combine orange juice, honey, minced shallot, and white-wine vinegar; season with salt and pepper.

Puree the mixture until smooth.

With the blender motor running, add extra-virgin olive oil in a steady stream until the dressing is emulsified.

In a large bowl, toss arugula, frisee, and radicchio with the dressing; season with more salt and pepper.

Serve the salad immediately.