This one is pretty much just an easy serving suggestion. Pork tenderloin is one of the easiest meats to prepare since it’s inherently tender… one just needs to be sure not to overcook it.
Here, I first browned the tenderloin in a bit of oil in a pan. Then I slathered the pork with mustard (Grey Poupon Country Dijon), a bit of olive oil, and freshly ground Tellicherry peppercorns, and cooked it for 25 minutes or so in a 325° F oven until it was about medium (still slightly pink) doneness.
I served the pork topped with a simple sauce made of the mustard, thinned with balsamic vinegar (if I recall correctly :) ). It was accompanied by a mixed green salad including boiled fingerling potatoes and blanched strips of red onion. (From the looks of them, these may be fat finger[ling] potatoes :) .) You can blanch the onion strips by tossing them in the water with the boiling potatoes just before draining. The pototoes and onion were tossed with a bit of Trader Joe’s Goddess Dressing. (See this post if you wish to make your own version of this great dressing.)
This dinner is easy and delicious. I could also imagine rolling the tenderloin in cracked peppercorn, as you might have a peppercorn-encrusted beefsteak.