Chili con carne with Gruyère AOP

Ingredients

• 1+1 tbsp olive oil
• 350 g ground beef
• 2 chopped onions
• 3 sliced celery stalks
• 150 g diced carrots
• 3 chopped garlic cloves
• 1 tsp cumin
• 1/2 tsp chili powder
• 3 tsp oregano
• 250 ml light beer
• 1 can (400 g) of tomatoes
• 1 can (400 g) of red kidney beans, rinsed and drained
• 1 small piece of dark chocolate
• Salt
• pepper
• 1 chopped red onion
• 50 g Gruyère AOP
• 125 g plain yogurt
• 1 bunch chopped coriander