Add 1 tbsp Extra Virgin Olive Oil into a large sauce pan over medium heat, add the onions and Neapolitan Herb balsamic cook until completely caramelized and golden brown, stirring periodically and adding a splash of water or Guinness as needed to deglaze the pan and prevent burning. For the best flavour, caramelize the onions slowly, for up to an hour, to bring out their sweetness without risking an acrid, burnt flavour.
Add the garlic and thyme and cook until fragrant, about a minute.
Add 1 tbsp of Extra Virgin Olive Oil, mix in the flour and let it cook for 2-4 minutes.
Add the stout and deglaze the pan.
Add the broth, grainy mustard, bay leaves, salt and pepper, bring to a boil, reduce the heat and simmer for 30 minutes.
Ladle the soup into oven-proof bowls on a baking sheet, top with the toasted bread and both cheeses, and broil until cheese melts, about 1-3 minutes.
Prep: 15 minutes
Cook: 50 minutes
Makes: 6 servings