Ingredients

• 1/3 cup (or more) olive oil
• 1/4 cup vegetable oil
• 1 cup pitted olives (such as Niçoise or Kalamata), chopped
• 1 tablespoon minced capers
• 1 garlic clove, minced
• 1 anchovy fillet packed in oil, drained, minced (optional)
• 2 pounds flatiron, flank, hanger, or skirt steak
• Kosher salt
• Zest and juice of 1 orange
• 1/4 cup thinly sliced shallots
• 2 tablespoons chopped fresh oregano
• 2 tablespoons minced garlic
• 2 tablespoons smoked paprika
• 2 tablespoons vegetable oil
• 1 tablespoon crushed red pepper flakes
• 4 large tomatoes (about 3 pounds), sliced 1/4" thick
• 1 shallot, thinly sliced into rings
• 1/4 cup (loosely packed) flat-leaf parsley leaves
• 1 tablespoon olive oil plus more for drizzling
• Flaky sea salt and freshly ground black pepper
• 1 bunch watercress, tough stems removed (about 4 cups)
• 1 tablespoon fresh lemon juice
• Ingredient info: Smoked paprika is sold at specialty foods stores and latienda.com.

Instructions

1. Stir 1/3 cup olive oil, next 4 ingredients, and anchovy, if using, in a small bowl. Add more olive oil for a thinner tapenade, if desired. (For a smoother sauce, purée tapenade in a food processor or blender.) Set aside.
2. For steak: Place steak in a large baking dish and season generously with salt. Stir orange zest and juice and remaining 6 ingredients in a small bowl to combine. Spread mixture evenly over both sides of steak and let marinate at room temperature for 1 hour. Build a medium-hot fire in a charcoal grill, or heat a gas grill to high. Grill steak, turning once, until nicely charred, about 5 minutes on each side for medium-rare. Transfer to a carving board and let rest for 5-10 minutes.
3. Place steak in a large baking dish and season generously with salt. Stir orange zest and juice and remaining 6 ingredients in a small bowl to combine. Spread mixture evenly over both sides of steak and let marinate at room temperature for 1 hour.
4. Build a medium-hot fire in a charcoal grill, or heat a gas grill to high. Grill steak, turning once, until nicely charred, about 5 minutes on each side for medium-rare. Transfer to a carving board and let rest for 5-10 minutes.
5. For tomatoes: Arrange tomatoes on a serving platter. Scatter shallot and parsley over; drizzle with oil and season with salt and pepper. In a medium bowl, toss watercress with 1 tablespoon each oil and lemon juice. Season watercress to taste with salt. Mound watercress on platter. Slice steak against the grain; transfer to platter with tomatoes and watercress. Spoon tapenade on steak and serve alongside.
6. Arrange tomatoes on a serving platter. Scatter shallot and parsley over; drizzle with oil and season with salt and pepper. In a medium bowl, toss watercress with 1 tablespoon each oil and lemon juice. Season watercress to taste with salt.
7. Mound watercress on platter. Slice steak against the grain; transfer to platter with tomatoes and watercress. Spoon tapenade on steak and serve alongside.