In this easy oven dinner, the potatoes and tenderloin roast simultaneously. Wrapping the lean pork with bacon helps flavor the meat and keeps it from drying out.
1. Arrange oven racks on bottom two slots in oven. Heat oven to 450 degrees F. Coat 15 x 10 x 1-inch jelly-roll pan and small roasting pan with cooking spray.
2. In bowl, combine potatoes and peppers. In small bowl, whisk 1 tablespoon mustard, oil, 1 tablespoon water, salt, pepper. Drizzle over potato mixture; toss. Spread in jelly-roll pan.
3. Spread 1 tablespoon mustard over pork. Arrange bacon over top, spacing slightly apart. Place in roasting pan.
4. Place pans in oven, potatoes on bottom rack, pork above. Roast in 450 degree F oven 30 minutes. Check pork at 20 minutes; if internal temperature is 150 degrees F, remove from oven. If not, leave in oven for another 5 to 10 minutes.
5. While pork and potatoes are roasting, prepare sauce: In small bowl, mix remaining 2 tablespoons mustard, 2 tablespoons water, mayonnaise, vinegar, garlic.
6. Toss potato mixture. Thinly slice pork. Serve with sauce.