Saute pork mince in 2 tablespoons olive oil until browned. Drain to remove excess oil. Remove from frypan and set aside. In frypan, heat 3 tablespoons olive oil, add onions and garlic then saute stirring until onions wilt down. Add tomato sauce, salt, pepper and chilli flakes to taste. Simmer about 5 minutes on low.
Stir in the chopped olives. Toast bread lightly under grill. Top with pork mix and sprinkle grated mozzarella over all. Grill about 3 minutes until cheese melts. Watch carefully with oven door open. Remove from grill, slice and serve.