1. To prepare pickled onions, pour water and vinegar into a stainless-steel pan or skillet with sides. (Do not use aluminum.) Add sugar, salt, and red pepper. Boil until salt and sugar are dissolved. Add red onion. Bring to a boil and remove from heat. Cool, then place in refrigerator.

2. Place grape seed oil in a heavy-bottom stainless-steel or cast-iron skillet on medium-high heat. Season steak with salt and pepper. Add steak to hot oil in skillet. Let sear without moving for 5 minutes. Flip and cook other side.

3. Remove from pan and rest 7-10 minutes. Slice into medallions crossways up the meat. Serve the steak with radishes, parsley, and pickled red onion. Finish with a drizzle of olive oil and a sprinkle of flake salt.