Onion Soup Gratinée · Celebrate Jacques

Ingredients

• ½ tablespoon unsalted butter
• 1 tablespoon olive oil
• 1 large onion, coarsely chopped, about 1½ cups
• 3 cups chicken stock, preferably homemade
• Freshly ground black pepper
• Fine sea salt
• 10 to 12 slices baguette, toasted
• 1½ cups grated Gruyère, Emmentaler or Swiss cheese