Turkish pide with mushrooms

Ingredients

• 2 Turkish flatbreads (300-350g in total)
• 2 clove garlic, crushed
• 2 tablespoon extra virgin olive oil, plus extra to serve
• 1/2 cup plain hummus
• 2 tablespoon roughly chopped parsley, plus extra to serve
• 1 medium red onion, finely sliced
• 250 gram (about 5) large flat mushrooms, finely sliced
• 125 gram fresh or aged mozzarella
• 1/2 teaspoon chilli flakes
• 1/2 teaspoon sumac – optional