- 1 12-ounce sirloin steak
- Sea salt and pepper
- ½ red onion, peeled and thinly sliced
- ½ cup buttermilk
- Olive oil
- 1 tablespoon Dijon mustard
- 1 tablespoon white wine vinegar
- 1½ pounds asparagus, ends trimmed and spears cut into 2-inch pieces
- 2 cups torn, day-old bread
- 6 to 8 radishes, washed and cut into quarters
Season steak on both sides with salt and pepper. Set aside. Place sliced onions in a bowl of cold water. Set aside. In a large measuring cup, whisk buttermilk, 3 tablespoons olive oil, mustard, and vinegar. Season with salt and pepper to taste. Set aside.
Fill a 10-inch cast iron skillet with water. Add 1 tablespoon salt. Bring to a boil over high heat. Add asparagus. Once the water returns to a boil, reduce heat and cook until crisp tender (1 to 2 minutes). Drain asparagus into a colander in the sink and run it under cold water until cool. Dump bowl of onions into the colander as well.
Place skillet back onto the stove over high heat. Rub both sides of the seasoned steak with olive oil and place it into the pan. Sear the steak well on one side (4 to 5 minutes). Reduce heat to medium, turn steak over, and cook it to your desired doneness. Transfer steak to a cutting board to rest for 10 minutes.
Add 3 tablespoons of olive oil to the pan which is still over medium heat. Toss torn bread into the pan. Cook, stirring until most sides of the pieces are crisp. Sprinkle with salt. Dump bread into a large bowl. Add asparagus, onions and radishes. Toss with dressing.
Divide salad among four plates. Slice steak against the grain very thinly. Divide steak pieces among the plates. Serve immediately.