Potato and Caramelized Onion Gratin | RICARDO

Ingredients

• 2 Spanish onions, diced
• ¼ cup (55 g) butter
• ½ cup (125 ml) white wine
• 1 tbsp (15 ml) tomato paste
• Salt and pepper
• 11 cups (1.7 kg) peeled and cubed potatoes
• ¼ cup (55 g) cold butter, cubed
• ½ cup (125 ml) 35% heavy cream
• ½ lb (225 g) firm washed-rind cheese, sliced
• 2 tbsp chopped fresh chives