Waste Not Want Not Gravy | BOSH!

Ingredients

• 1 tbsp miso paste
• 2 tbsp olive oil
• the spines from a savoy cabbage
• 1 onion
• the cuttings from brussels sprouts
• 4 garlic cloves
• 1 tbsp Marmite
• 1 tsp gravy browning
• 1 tbsp tomato purée
• 1 tbsp nutritional yeast
• 2 tbsp plant-based gravy granules
• 2 tsp brown sugar
• 1 litre drained carrot water
• 1 sprigs of sage
• 2 bay leaves
• 5 dried porcini mushrooms
• 2 tbsp cornflour
• 4 tbsp water