Instructions

1. Heat the butter in a heavy base saucepan over low heat and add the onions, stirring well.
2. Add 1 quarter tsp salt and some freshly ground black pepper and stir again. Turn the heat down to its lowest setting and cook the onions for 45 - 60 minutes, stirring every 5 minutes or so, until you get a dark caramel colour or the colour you prefer the onions to be. Dark is definitely better but not burnt!
3. Add the flour and mix it well into the onions for about a minute.
4. Next goes half the cider, to loosen the roux you've just made with the flour, scraping the bottom well.
5. Add the rest of the cider, the stock and the balsamic vinegar, stir and let it come to boil, then simmer, covered, for 30 minutes.
6. Prepare the cheesy croutons. Rub the slice of garlic on both sides of your baguette slices and toast/grill them on both sides under the grill (broiler) until crispy. Set aside until needed.
7. Check seasoning, turn the heat off, add the splash of brandy now, if using.
8. Ladle the onion soup into individual bowls, place two croutons into each bowl, on the soup.
9. Sprinkle both cheeses liberally over the croutons and soup and place the bowls under a hot grill until the cheese is beautifully melted and bubbling.
10. Top with some freshly ground black pepper and serve immediately, but be warned, the bowls will be über hot!