Vegan Celeriac Soup with Apple, Lemon & Thyme - The Pesky Vegan

Ingredients

• 1 tablespoon olive oil
• 2 onions, chopped
• 1 medium celeriac, peeled and diced ((approx. 1.5 lb / 700 grams))
• 2 large eating apples, peeled, cored, and diced ((or 3 medium))
• 1 medium potato, peeled and diced ((optional))
• 5 cups (1.2 litres) vegan stock
• 1 teaspoon dried thyme
• 2 bay leaves
• 3 tablespoons nutritional yeast
• ¾ cup (200 ml) plant-based milk
• Grated zest of 1 lemon ((save the juice to serve))
• Salt and pepper, to taste
• Small handful fresh parsley, to serve ((optional))