Preheat oven to 200°C fan forced. Grease two, 12 hole mini muffin tray with oil spray.
Heat a large frying pan over high heat until hot. Add oil and mushrooms and cook, shaking pan often, for 10 minutes. Add the ginger and cook 30 seconds. Add the green onions and stir to combine. Transfer to a large bowl, set aside to cool.
Add the mince, hoisin sauce, tomato sauce, egg, breadcrumbs and coriander to the mushroom mixture. Season with salt and pepper. Mix well. Press mixture into muffin holes so they are full to the top.
Bake for 15-20 minutes or until firm in the centre. Stand in the pan for 5 minutes before turning onto a rack. Repeat with remaining mixture. Serve warm topped with extra coriander and hoisin sauce.