This briny, tangy sandwich, from Joanne Chang of Flour Bakery + Café in Boston, benefits from sitting awhile after assembly. The oils from the tapenade will seep into the bread, making it moist but not soggy, and the sharp flavors of pickled fennel, capers, and olives will mellow pleasantly.
- 1⁄4 cup rice wine vinegar
- 3 tbsp. sugar
- 1 tsp. kosher salt
- 1 fennel bulb, trimmed and cut into 1/4″ pieces
- 1⁄4 cup capers, drained and minced
- 6 tbsp. olive oil
- 2 tbsp. minced chives
- 1 1⁄2 tbsp. Dijon mustard
- 2 (4 oz.) cans tuna in water, drained
- 2 lemons, zested and juiced
- 2 sprigs rosemary, minced
- Kosher salt and freshly ground black pepper, to taste
- 1⁄2 Whole-wheat baguette, halved lengthwise and then crosswise
- Baby arugula, for serving
- Olive tapenade, for serving
- Make the pickled fennel: Combine vinegar, sugar, salt, and 1⁄2 cup water in a 1-qt. saucepan over high; cook until sugar has dissolved, 3 minutes. Pour over fennel; cool.
- Make the sandwich: Stir 1⁄3 cup pickled fennel, the capers, oil, chives, mustard, tuna, lemon zest and juice, rosemary, salt, and pepper in a bowl. Spread tuna salad on bottom of baguette, then top with arugula, tapenade, and top of baguette.