Place the paprika, lemon rind, lemon juice and oil in a small bowl and stir to combine. Season. Reserve half the paprika mixture in a small bowl.
Brush the lamb with the remaining paprika mixture.
Cook the peas in a large saucepan of boiling water for 2 mins or until heated through. Refresh under cold water. Drain well.
Place the dip, coriander, chilli, if using, and 1 cup (120g) peas in a food processor. Process until smooth. Transfer to a small bowl. Cover with plastic wrap. Place in the fridge to chill.
Heat a barbecue grill or chargrill on high. Cook the flatbreads, in batches, for 30 secs each side or until lightly charred. Transfer the flatbreads to a plate. Cover with foil to keep warm.
Cook the lamb on the grill for 4 mins each side for medium or until the lamb is cooked to your liking. Transfer the lamb to a plate. Cover with foil and set aside for 5 mins to rest. Thickly slice.
Place the remaining peas in a small bowl. Use a fork to crush. Season.
Arrange the flatbreads on a serving platter. Top with pea hommus, rocket, lamb and tomato. Sprinkle with the crushed peas and coriander. Drizzle with the reserved paprika mixture.