Heat broiler. In a medium bowl, combine the meat, apricots, coriander, chopped onion, ½ teaspoon salt, and ¼ teaspoon pepper.
Form the meat into 1½-inch balls (about 20) and place them on a broilerproof baking sheet. Broil until cooked through, 6 to 8 minutes.
Meanwhile, place the couscous in a bowl. Add 1 cup hot tap water, cover, and let sit for 5 minutes. Fluff with a fork.
In a small bowl, mix together the oil, lemon juice, and ¼ teaspoon each salt and pepper.
Serve the couscous with the meatballs, tomatoes, cucumber, Feta, and sliced onion. Drizzle with the dressing.