Onion soup with cheese

Ingredients:

• 2 tbsp (30 g) butter
• 8 cups (800 g) red onion, thinly sliced
• 1 tbsp. (170 gr.) grated sweet potato (sweet potato)
• 250 ml of red wine
• 1 liter of beef broth
• 1 - 2 tsp chopped fresh rosemary
• 6 slices of white bread, toasted in the oven
• 135 g aged cheddar cheese, grated
• 135 g Swiss cheese, grated

Preparation:

1. In a saucepan, sauté the onion in butter for 10 minutes, stirring occasionally. Add the potatoes and cook for 3-4 minutes. Add the wine and simmer, stirring occasionally, until the liquid has reduced by half. Add the stock and rosemary, bring to a boil, and simmer over low heat for 15 minutes.
2. Preheat oven to 230 C. Ladle the soup into ceramic cups, add slices of bread and sprinkle a handful of both types of cheese on top.