Cooking Time: 60 Minutes
1 (5-pound) top sirloin roast
salt and freshly ground black pepper
1 teaspoon dried thyme
2 pounds red potatoes, halved or quartered
2 teaspoons olive oil
1 teaspoon very finely chopped fresh rosemary, plus more for garnish
1. Start by making sure your roast will fit into the air fryer basket without touching the top element. Trim it if you have to in order to get it to fit nicely in your air fryer. (You can always save the trimmings for another use, like a beef sandwich.)
2. Preheat the air fryer to 360°F.
3. Season the beef all over with salt, pepper and thyme. Transfer the seasoned roast to the air fryer basket.
4. Air-fry at 360°F for 20 minutes. Turn the roast over and continue to air-fry at 360°F for another 20
5. Toss the potatoes with the olive oil, salt, pepper and fresh rosemary. Turn the roast over again in the air fryer basket and toss the potatoes in around the sides of the roast. Air-fry the roast and potatoes at 360°F for another 20 minutes. Check the internal temperature of the roast with an instant-read thermometer, and continue to roast until the beef is 5° lower than your desired degree of doneness. (Rare – 130°F, Medium – 150°F, Well done – 170°F.) Let the roast rest for 5 to 10 minutes before slicing and serving. While the roast is resting, continue to air-fry the potatoes if desired for extra browning and crispiness.
6. Slice the roast and serve with the potatoes, adding a little more fresh rosemary if desired.