1. Rinse the herbs under cold water. Pat them dry and chop them. Cut the pork tenderloin into large cubes. Place them in a shallow dish. Add the herbs and olive oil. Massage the meat to fully infuse it with all the flavors. Cover and refrigerate for 1 hour.
2. Soak the couscous in hot water according to the instructions on the packaging. Chop the parsley. Peel the tomatoes, dice them, and also dice the preserved lemon. Gently mix the couscous, parsley, tomatoes, and preserved lemon in a salad bowl. Drizzle with lemon juice and olive oil, season with salt and pepper. Chill until ready to serve.
3. Mix the yogurt and chopped mint leaves, season with salt and pepper. Chill in the refrigerator. Preheat the oven to 200°C (th 6-7). Assemble the skewers. Rinse the lemons, quarter them, and skewer them with the meat, alternating. Place them back in the dish, pour the marinade over them, and bake for 30 minutes. Flip them halfway through cooking. Serve with the tabbouleh and sauce.