Cajun Prime Rib Roast with Baby Yellow Potatoes

  • Prep 20 mins
  • Total 1h 45 mins
  • Easy
  • Serves 8

TIP: This recipe is written for a medium rare center (130°F–135°F). If you prefer a medium center, add 10 minutes to the cook time at step 6.

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  • 3 tablespoons Cajun seasoning
  • 3 tablespoons brown sugar
  • 3 tablespoons kosher salt, divided
  • 1 tablespoon ground black pepper
  • 4-5 pounds uncooked boneless prime rib roast, fat trimmed
  • 3 pounds baby yellow potatoes, cut in half
  • 1 tablespoon onion powder
  • 1 tablespoon garlic powder
  • 3 sprigs fresh thyme
  • 2 tablespoons canola oil


  • Two Large Bowls
  • Ninja Sheet Pan
  • Step 1

    In a mixing bowl combine Cajun seasoning, brown sugar, 2 tablespoons salt, and pepper. Stir well to combine. Pat prime rib dry with paper towels. Rub Cajun mixture all over beef, coating evenly. 

  • Step 2

     In a separate mixing bowl, toss potatoes with remaining 1 tablespoon salt, onion powder, garlic powder, thyme, and oil. Spread potatoes out evenly in air fry basket. 

  • Step 3

    Plug thermometer into jack on the underside of the door handle. Select WHOLE ROAST and set temperature to 450°F. Select PRESET, then use the FUNCTION button to select BEEF. Use the temperature buttons to select desired doneness. Insert thermometer horizontally into thickest part of the roast (see thermometer placement instructions on page 7). Press START/STOP to begin preheating. 

  • Step 4

    Nest the Ninja® Roast Tray in the Ninja® Sheet Pan, then place roast on tray.

  • Step 5

    When the unit has preheated, place pan on wire rack and slide basket into the rails of Level 4. Close oven door to begin cooking. 

  • Step 6

    After 25 minutes, select WHOLE ROAST, set temperature to 250°F, and set time to 1 hour. Press START/STOP to begin cooking. 

  • Step 7

    When unit beeps to signal the roast has reached its doneness, transfer to a plate or cutting board with thermometer still inserted. Allow to rest for 10 minutes or until thermometer indicates final temperature has been reached.