Barbecued Flat Mushrooms with Prawns | Australian Mushrooms

Ingredients

• 1/4 cup extra virgin olive oil
• 1 large lemon, find finely grated, juiced
• 2 tsp caster sugar
• 3 tsp Dijon mustard
• 8 medium king green prawns, tail intact, peeled, deveined
• 6 small flat mushrooms, stems trimmed
• 2 tbs finely chopped flat-leaf parsley
• ½ small garlic clove, very finely chopped
• Extra virgin olive oil, to serve, optional
• Crusty bread, to serve