Potato, onion and mozzarella pizza - Potatoes New Zealand

Ingredients

• 1 premade pizza base
• 1 Tbsp olive or vegetable oil
• 4 medium general purpose potatoes, cooked, cooled and sliced
• 1 onion, peeled and finely sliced
• ½ cup chopped, pitted black olives
• 1 cup grated mozzarella cheese