Grilled Steak and Watercress Sandwiches

Ingredients

• 1-¼ lb. flat-iron or top sirloin steak
• 1 large tomato (about ½ lb.), cored and thinly sliced
• ¼ cup chopped cornichons or dill pickles
• Kosher salt and freshly ground black pepper
• 1 tsp. Dijon mustard
• 3 Tbs. olive oil; more for the bread
• ½ bunch watercress (about 3 oz.), thick stems discarded
• + 4 more ingredients
• • 1 Tbs. red wine vinegar
  • 2 Tbs. finely chopped shallot
  • ¼ lb. sliced Muenster cheese
  • 1 large ciabatta loaf (about 1 lb.)

Prepare a medium (375°F) gas or charcoal grill fire. Season the steak generously with salt and pepper. Put the tomato slices on a plate, sprinkle with 1/2 tsp. salt, and set aside. Whisk the vinegar and the mustard in a small bowl. Whisk in the olive oil in a slow stream until emulsified. Stir i...

View full recipe at Fine Cooking