Combine all ingredients in a medium bowl and season with salt and pepper to taste.
Preheat a grill pan over high heat until smoking. Brush the steaks with olive oil and season with salt and pepper, to taste. Grill for 4 to 5 minutes on one side until golden brown, turn over, reduce heat to medium and continue cooking for 5 to 6 minutes for medium-rare doneness.
Whisk together the vinegar and mustard in a small bowl. Slowly whisk in the olive oil and season with salt and pepper to taste. Toss the watercress in a few tablespoons of the dressing and arrange on a platter. Top with slices of the tomatoes and onions and drizzle with the remaining dressing. Sprinkle with the blue cheese.
Copyright 1999 Bobby Flay. All Rights Reserved.
Pairs well with Cabernet Sauvignon