Preparation
Step 1
To make the soup, set your largest saucepan over a high heat. Add the butter and oil. Once the better has melted, tip in the onions. Stir to coat, cook for 5 minutes then reduce the heat to medium. Cook for 45 minutes, stir in the garlic then cook for a further 15 minutes – you want the onions to be really caramelised.
Step 2
Increase the heat to high and pour in the vinegar. Stir to coat the onions, then add the stock and bouquet garni. Bring to the boil, add the pasta and cook for 2 minutes less than pack instructions.
Step 3
Add the kale, cook for 2 minutes to wilt, then stir in the tomatoes.
Step 4
Ladle the soup in to individual soup bowls. Top with 2 slices of bread and a mound of cheese. Drizzle with olive oil then grill for 2-3 minutes until the cheese is bubbling.