Ingredients:

  • 2 large yellow onions, thinly sliced (about 600g / 21 ounces)
  • 2 tablespoons unsalted butter (30g / 1 ounce)
  • 1 tablespoon olive oil (15ml / 0.5 fluid ounces)
  • 1/2 teaspoon granulated sugar (2.5g / 0.09 ounces)
  • 1/4 teaspoon kosher salt (1.5g / 0.05 ounces)
  • 1/4 cup dry sherry or dry white wine (60ml / 2 fluid ounces)
  • 2 cups beef broth (473 ml / 16 fluid ounces)
  • 1 pound elbow macaroni (454g / 16 ounces)
  • 4 tablespoons unsalted butter (60g / 2 ounces)
  • 4 tablespoons all-purpose flour (30g / 1 ounce)
  • 3 cups whole milk (710 ml / 24 fluid ounces)
  • 1/2 teaspoon kosher salt (3g / 0.1 ounces)
  • 1/4 teaspoon freshly ground black pepper (1.5g / 0.05 ounces)
  • 1/4 teaspoon ground nutmeg (0.7g / 0.02 ounces)
  • 8 ounces Gruyère cheese, shredded (227g / 8 ounces)
  • 4 ounces sharp cheddar cheese, shredded (113g / 4 ounces)
  • 1/2 cup shredded Gruyère (56g / 2 ounces)
  • 1/4 cup panko breadcrumbs (20g / 0.7 ounces)
  • 2 tablespoons melted butter (30g / 1 ounce)

Instructions:

  1. Melt butter and olive oil in a large skillet or Dutch oven over medium heat. Add onions, sugar, and salt. Cook, stirring occasionally, until onions are deeply golden brown and caramelized (about 30-40 minutes). Deglaze with sherry/wine, scraping up any browned bits.
  2. Add beef broth to the onions and bring to a simmer. Reduce heat and simmer for 10 minutes to allow the flavors to meld. Remove from heat and set aside.
  3. Cook macaroni according to package directions until al dente. Drain well and set aside.
  4. Melt butter in a large pot over medium heat. Whisk in flour and cook for 1-2 minutes to form a roux. Gradually whisk in milk until smooth. Bring to a simmer, stirring constantly, until thickened (about 5-7 minutes). Reduce heat to low.
  5. Remove from heat and stir in salt, pepper, and nutmeg. Gradually stir in Gruyère and cheddar cheese until melted and smooth.
  6. Add cooked macaroni and caramelized onions (reserving a little for topping, if desired) to the cheese sauce. Stir to combine. Pour into a greased 9x13 inch baking dish. Top with reserved caramelized onions, shredded Gruyère, and panko breadcrumbs (if using). Drizzle with melted butter.
  7. Bake in a preheated oven at 350°F (175°C) for 20-25 minutes, or until golden brown and bubbly.
  8. Let cool slightly before serving the french onion mac and cheese.