Hearty Vegan Stew (One-Pot Recipe) - The Pesky Vegan

Ingredients

• 1 tablespoon olive oil ((or other cooking oil))
• 2 medium red onions, peeled and thinly sliced
• 2 large carrots, scrubbed, ends trimmed, and chopped into 1 cm chunks
• 3 sticks celery, halved lengthways and chopped into 1 cm chunks
• Approx. 400 g mushrooms, quartered or cut into small chunks ((chestnut, closed cup, or button))
• 4 cloves garlic, finely chopped
• Approx. 500 g Maris Piper potatoes, scrubbed and cut into 1cm chunks
• 150 ml red wine ((ideally vegan, optional))
• 1.2 litres vegan stock
• 2 tablespoons Henderson's Relish ((or half the amount of red wine vinegar, see notes))
• 1 tablespoon Marmite ((or other yeast extract if GF))
• 2 bay leaves
• 5-6 sprigs fresh thyme ((or 1 teaspoon dried))
• 1-2 sprigs fresh rosemary ((or 1 teaspoon dried))
• 2x 400 g tins green lentils, drained
• 1 tablespoon wholegrain mustard
• Approx. 150 g curly kale, sliced ((shop-bought is often pre-sliced))
• 4 tablespoons cornflour ((or plain flour – see notes))
• 4 tablespoons cold water
• Salt and pepper, to taste