French Onion Soup

Ingredients

  • 2 lb onions halved lengthwise, then thinly sliced lengthwise
  • 2 cloves garlic, chopped
  • 5 - 6 sprigs fresh thyme
  • 2 bay Leaves
  • ½ tsp fine-grain sea salt + more to taste
  • ¼ cup unsalted butter
  • 2 tsp flour (any variety will work)
  • ¾ cup dry white wine (red wine is great in this soup as well)
  • a small splash of balsamic vinegar
  • a small splash of Worcestershire sauce
  • 4 cups beef broth
  • 1 ½ cups water
  • ½ tsp freshly ground black pepper
  • 6 ½-inch-thick diagonal slices of baguette
  • 1 (½-lb piece) Gruyère, Comte, or Emmental
  • 2 Tbsp finely grated Parmigiano-Reggiano

Instructions

  • Cook onions, garlic, thyme, bay leaves, and salt in butter in a 4- to 5-quart heavy pot over moderate heat, uncovered, stirring frequently until onions are very soft and deep golden brown (~ 45 minutes)
  • Add flour and cook, stirring, 1 minute.
  • Add the wine and cook, stirring, 2 minutes.
  • Add the broth, water, balsamic vinegar, Worcestershire sauce, and pepper
  • Reduce the heat to low and simmer, uncovered, stirring occasionally (30 minutes)
  • While soup simmers, put oven rack in middle position and preheat oven to 350°F.
  • Arrange bread in 1 layer on a large baking sheet and toast, turning over once, until completely dry (~ 15 minutes)
  • Remove croûtes from the oven and preheat broiler.
  • Put soup crocks in a shallow baking pan. Discard bay leaves and thyme from soup and divide soup among crocks
  • Float a croûte in each.
  • Slice enough Gruyere (~ 6 oz total) with a cheese plane to cover tops of crocks, allowing ends of cheese to hang over rims of crocks, then sprinkle with Parmigiano-Reggiano.
  • Broil 4 to 5 inches from heat until cheese is melted and bubbly (~ 1 to 2 minutes)