Basil Chive Aioli
- 1 oil-packed anchovy fillet
- Kosher salt
- 1 cup mayonnaise
- 3 tablespoons fresh lemon juice
- 2 garlic cloves, finely grated
- ¼ cup chopped basil, plus more for serving
- 2 tablespoons chopped chives, plus more for serving
- Freshly ground black pepper
Pork and Assembly
- 2 tablespoons fennel seeds
- 1 teaspoon crushed red pepper flakes
- 2 tablespoons Diamond Crystal or 3½ teaspoons Morton kosher salt, plus more
- 2 pork tenderloins (about 1½ pounds each)
- Vegetable oil (for grill)
- 1 ciabatta loaf, halved lengthwise
- 6 cups mature arugula leaves with tender stems
- Torn basil leaves, chopped chives, and lemon wedges (for serving)
- Using the flat side of a knife, smash anchovy and ½ tsp. salt on a cutting board until a paste forms. Scrape into a medium bowl. Add mayonnaise, lemon juice, garlic, ¼ cup basil, and 2 Tbsp. chives and whisk to combine. Season with salt and pepper; cover and chill until ready to serve.
- Grind fennel seeds and red pepper in spice mill or with mortar and pestle until coarsely ground. Transfer to a small bowl. Mix in 2 Tbsp. salt. Rub mixture all over pork and let sit, uncovered, 1 hour, or chill up to 8.
- Prepare a grill for medium heat; thoroughly clean grates and brush with oil. Grill pork, turning every 4 minutes, until lightly charred on all sides and an instant-read thermometer inserted into the center of the loin registers 130°, 15–20 minutes. Let rest 10 minutes, then cut into very thin slices.
- Grill bread halves on both sides until lightly charred and warmed through, about 1 minute per side.
- Spread about ½ cup aioli over cut sides of both bread halves. Layer arugula over, then top with sliced pork, basil, chives, and a squeeze of lemon. Serve any remaining aioli alongside.