Tomato soup with cheese Marmite toast

Name: Tomato soup with cheese & Marmite toast
Ingredients: 1 tbsp olive oil; 1 medium onion, roughly chopped; 1 tsp dried oregano; 1 garlic clove, chopped; 1 small bunch basil, leaves picked; 400g can plum tomatoes; 2 slices of crusty bread, toasted; 2 tsp Marmite; 50g parmesan or vegetarian alternative, grated