Ingredients

· 2 tablespoons vegetable oil

· 4 onions

· 4-5 garlic cloves

· 1 tablespoon marmite

· Few sprigs thyme

· 2 l vegetable stock

· 1 tablespoon light brown sugar

· 1 tablespoon balsamic vineger

· For Cheese Toppers

· 4 slices sourdough

· 2 teaspoons Marmite

· 75 g gruyere cheese

· Few sprigs thyme

Method

Heat the oil in a pan and cook the onions with a pinch of salt over a low-medium heat for 20 minutes, stirring occasionally. Turn the heat to low and cook for 40 minutes until the onions are caramelised. Stir in the garlic and cook for five minutes to soften, then add the Marmite, thyme and stock and bring to a simmer. Cook gently for 15 minutes, then season with the sugar, vinegar, salt and pepper. Heat the grill to high. Toast the bread on both sides, then spread over the Marmite, sprinkle over the cheese and thyme, and grill until the cheese is bubbling. Ladle the soup into bowls, top with the Marmite toppers and scatter with thyme leaves.