Petit Trois's French Onion Soup Recipe | Epicurious

Ingredients

• 6 pound veal neck or beef bones
• 1 tablespoon grapeseed or vegetable oil
• 2 large onions, chopped
• 6 celery stalks, chopped
• 1 pound carrots, peeled, chopped
• 1/4 cup tomato paste
• 1 head of garlic, halved crosswise
• 4 sprigs thyme
• 1 bay leaf
• 3 tablespoons grapeseed or vegetable oil
• 1 tablespoon unsalted butter
• 4 pounds onions, thinly sliced
• Kosher salt, freshly ground pepper
• 3 tablespoons dry Sherry
• 6 sprigs thyme
• 4 1/2"-thick slices baguette, toasted
• 4 1/8"-thick slices Gruyere
• 4 1/8"-thick slices Emmenthal cheese
• Cheesecloth
• French onion soup bowls or 8-ounce ramekins