PreparationFor pork: Combine first 7 ingredients in large resealable plastic bag; shake to blend. Add pork to marinade; seal bag. Chill overnight, turning bag occasionally. For sauce: Stir first 7 ingredients in medium bowl to blend. Season sauce to taste with salt and pepper. Cover and chill until ready to use, up to 1 day. Prepare barbecue (medium heat). Remove pork from bag. Grill until thermometer inserted into center of each tenderloin registers 145°F, about 18 minutes. Transfer to work surface; let stand 10 minutes (temperature will rise 5 to 10 degrees). Thinly slice into rounds. Grill pitas until warmed through and softened, about 2 minutes per side. Cut pitas in half. Fill pita halves with pork, drizzle with sauce, then tuck in onion and arugula. Serve, passing remaining sauce separately.
PreparationFor pork: Combine first 7 ingredients in large resealable plastic bag; shake to blend. Add pork to marinade; seal bag. Chill overnight, turning bag occasionally. For sauce: Stir first 7 ingredients in medium bowl to blend. Season sauce to taste with salt and pepper. Cover and chill until ready to use, up to 1 day. Prepare barbecue (medium heat). Remove pork from bag. Grill until thermometer inserted into center of each tenderloin registers 145°F, about 18 minutes. Transfer to work surface; let stand 10 minutes (temperature will rise 5 to 10 degrees). Thinly slice into rounds. Grill pitas until warmed through and softened, about 2 minutes per side. Cut pitas in half. Fill pita halves with pork, drizzle with sauce, then tuck in onion and arugula. Serve, passing remaining sauce separately.