Steps for Preparation

1. Adjust a rack to center of the oven and preheat to 450°F.
2. Season sirloin with salt and pepper. Heat a skillet over medium heat until hot and then add oil.
3. Add steak and sear the meat until golden brown, bout 3-4 minutes on each side. Remove seared meat to a plate and add onions and prosciutto to the pan. Brown onions, stirring frequently, about 8 minutes.
4. Once the onions have browned, remove the pan from the heat. Mound the onions into the center of the pan and place the meat directly over the onion mixture. Transfer pan to the oven.
5. Check for doneness using the Cook'd Right^® Sensor.
1. Quickly insert dark sensor tip into center of meat. Wait 5-10 seconds.
2. Remove sensor tip and check color.
3. Continue checking with the same sensor until done.
4. Discard sensor when finished.
6. Sirloin is rare when tip of sensor is 1/3 orange. Medium when tip is 2/3 orange. Well done if fully orange.
7. Sirloin is medium rare at about 20 minutes.
8. Remove the cooked sirloin to a clean plate. Add the port, water, and thyme to the onion and prosciutto; simmer port to half its original volume.
9. Cut the sirloin into thin slices. Add any collected meat juices to the port sauce. Place the meat on a warm serving platter.
10. Top sirloin with port sauce. Garnish with Stilton cheese and serve immediately.