1. Dice the onions and mushrooms.
2. Add 10ml of oil to the saucepan and sweat the onions for 10 minutes until soft.
3. Add the mushrooms and cook on a low heat.
4. Continue to cook the mushrooms for 20-30 minutes until dark brown and all the liquid has evaporated.
5. Add the black garlic and blend with a stick blender until smooth.
6. Add the remaining oil, pulled oats, miso and smoked paprika.
7. Cook for 10 minutes until cooked and all ingredients are well combined.
8. Taste and season with salt and pepper.
9. Allow mix to cool to room temperature. Roll into a sausage, wrap in cling film and refrigerate for an hour.
10. Mix maple syrup with oat milk.
11. Roll sausage into puff pastry, sealing with the milk mix.
12. Glaze the top of the sausage roll, then top with sesame seeds.
13. Bake for 25 minutes at 180°C until golden brown and piping hot throughout.