Coat a large saute pan with oil and over medium heat, saute the onions until soft. Add the ground lamb and cook until browned, breaking up the chunks with a wooden spoon. Drain well and place in a serving bowl. Stir in the onion powder and black pepper. Allow to cool and then add pineapple, green pepper, tomatoes, cucumber, cilantro and feta cheese. Adjust the seasoning and serve with pita bread or crackers.