Caramelized Onion Soup with Gruyère and Garlic Crostini

Preparation

Step 1
Heat butter in large deep sauté pan or Dutch oven over medium heat until melted. Add onions and salt, stirring to coat with butter. Lower heat to medium-low, cover pan and cook 15 minutes, or until onions are softened. 

Step 2
Uncover pan; continue to cook slowly until onions are deep golden brown and very soft, stirring frequently and scraping the bottom of the pan, about 30 minutes.

Step 3
Sprinkle flour over onions, stir and cook a few minutes until flour is absorbed. Pour in stock, bring to a simmer and cook 10 minutes to thicken soup slightly. Stir in ham; season to taste with salt and pepper. 

Step 4
Heat broiler; rub each slice of bread with a garlic clove and brush on both sides with olive oil. Toast the bread for a few minutes on each side until golden. 

Step 5
Portion soup into heatproof bowls; top each bowl with 1/2 cup cheese and place on a sheet pan under the broiler until cheese is melted and bubbling. Place a crouton on top of each bowl of soup and serve immediately.