Set pressure cooker to "sear", add oil, adjust time to 15 minutes, and press "start/stop". When hot, add lamb. Sear each side. Add bay leaf, marjoram, sage, garlic, tomatoes, olives, ginger, thyme, and stock.
Close and lock lid, set pressure cooker to "meat/stew", adjust time to 45 minutes, and press "start/stop".
When done, quick release and make sure all pressure is released before opening lid. Carefully open lid and add potatoes.
Close and lock lid, set to "potatoes", adjust time to 8 minutes, and press "start/stop".
When done, quick release and make sure all pressure is released before opening lid. Carefully open lid and remove lamb. Transfer meat and potatoes to plate.