1 boneless center-cut pork loin roast (2 pounds)
Coarse salt and ground pepper
3 teaspoons Dijon mustard
1 1/2 tablespoons plain breadcrumbs
1 pound frozen pearl onions, thawed
1 tablespoon olive oil

1. Preheat oven to 450°.
Rub pork with salt, pepper, and 2 teaspoons mustard.
On a plate, season breadcrumbs with salt and pepper.
Coat top and sides of roast with breadcrumbs, leaving ends uncoated.

2. In a 9-by-13-inch roasting pan, toss onions with oil;
season with salt and pepper.
Place pork in center of pan; roast 15 minutes.
Turn onions; cook 10 minutes.
Add 1/4 cup water; stir onions to coat.
Continue cooking until onions are caramelized,
pork juices run clear,
and an instant-read thermometer inserted
into the thickest part of the meat registers
140°, 10 to 15 minutes more.
Remove pork and onions from pan;
let meat rest 20 minutes before slicing.

3. While meat is resting,
add 1/2 cup water and remaining teaspoon mustard to pan.
Cook over medium heat, scraping up browned bits.
Stir until sauce is fully blended,
3 to 5 minutes; serve with pork and onions.

Note:
Cook the onions until they are caramelized.
If the pork is done first, remove it, and leave the onions in a little longer.