Escarole and potato soup

Ingredients

• 500 gram fresh escarole
• 1 leek
• about 5 medium-sized floury potatoes
• 2 garlic cloves
• 2 tablespoons curry powder
• 1 teaspoon ground ginger
• olive oil
• 200 ml dry white wine
• 1,5 liter chicken or vegetable stock
• pepper and salt to taste
• large handful of grated Gruyere cheese