Beef Medallions with Caramelized Onions and Portobello Caps

Instructions

1. Preheat oven to 400º. Coat the bottom of a heavy Dutch oven with cooking spray. Place the 4 slices of onions on the bottom and drizzle balsamic vinegar on each. Sprinkle brown sugar on top and rub it into the onions. Cover and cook for 45 minutes. Uncover and cook for another 15 until caramelized. Set aside.
2. Preheat broiler to high. Drizzle olive oil on the mushroom cap and sprinkle with 1 Tbsp of parsley. Broil for 6 to 8 minutes until the mushroom caps are tender. Remove from broiler and set aside.
3. Prepare a grill pan with cooking spray. Heat pan on high. Salt and pepper the filet medallions and rub in the seasoning. Place the medallions in the hot grill pan (water should sizzle when the pan is hot enough), and cook on one side for 4 to 5 minutes until moisture appears on the surface. Turn the beef over and cook for 4 to 5 minutes more for rare steak. (Cook another 2 minutes for medium.) Remove the medallions and place them on a cutting board with a loose aluminum foil tender over the top and allow to rest for at least 10 minutes.
4. Place a mushroom cap on each plate, a beef medallion on top of that, and finish with a slice of caramelized onion. Sprinkle the rest of the parsley over the stacks.