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French onion soup may be pretty simple, but there’s something so special about that combination of flavors. The way the onions become sweet and lose all their sharpness, the contrast of the beef stock with the nutty Swiss cheese… We absolutely adore it. But since it can’t be all soup all the time, we’ve taken that fantastic flavor combo and converted it into casserole form. And, oh boy, is it a winner! All of those flavors we love with the addition of comforting pasta and hearty chicken… it’s a weeknight dinner you’ll keep coming back to.

Since this takes a mere thirty minutes to bake and not much longer to throw together (and since the whole family loves it), we find ourselves making this one pretty frequently. You start by cooking the onions in some butter, before adding some seasoning and letting those onions get nice and caramelized. We find that some balsamic vinegar really helps deepen the flavor here, though we still add plenty of hearty beef stock.

Cooked pasta and chicken are tossed in the thickened sauce and topped with a generous helping of Swiss cheese. (This is a great use for leftover rotisserie chicken – maybe our very favorite one!) As that all bakes in the oven, you mix up some breadcrumbs and butter as a crunchy topper… and we’ll just say that it’s a component you definitely don’t want to skip. It mimics the toasted slice of bread in the soup version and it lends the entire dish a subtle crunchy texture that really brings it all home. As far as family-friendly bakes go, this is one you don’t want to miss.

Serves 8

1 hour

Rated 5 out of 5
Rated by 1 reviewers
  • 10 oz. fettuccine noodles, broken into thirds, cooked and drained
  • 2 cups cooked chicken, shredded
  • 2 1/2 cups beef broth
  • 2 large onions (5-6 cups), halved and thinly sliced
  • 1/4 cup (1/2 stick) unsalted butter
  • 1 tablespoon fresh thyme, minced
  • 3 tablespoons all-purpose flour
  • 2 cups swiss cheese, grated
  • 1/2 tablespoon balsamic vinegar
  • 1/2 teaspoon garlic powder
  • kosher salt and freshly ground pepper, to taste
  • Topping:
  • 1 cup panko or seasoned breadcrumbs
  • 2 tablespoons unsalted butter, melted
  1. Preheat oven to 350º F and lightly grease a 9x13-inch baking dish with non-stick spray.
  2. In a large pan or skillet over medium-high heat, melt butter and sauté onions for 6-8 minutes, or until softened. Season with thyme, garlic powder, salt and pepper.
  3. Reduce heat to medium and cook, stirring frequently, until onions have darkened and caramelized. Add balsamic vinegar and cook for another 5 minutes.
  4. Once caramelized, sprinkle flour over the onions and stir to incorporate. Cook for 2-3 minutes, or until flour has cooked, then stir in beef broth. Bring to a boil, then reduce heat to low and simmer for 3-5 minutes, or until thickened.
  5. Remove from heat and stir in chicken and cooked pasta.
  6. Transfer pasta mixture to baking dish and top with Swiss cheese. Place baking dish in oven and bake for 20 minutes.
  7. While cooking, whisk together melted butter and seasoned breadcrumbs.
  8. Remove baking dish from oven and top with breadcrumb topping. Return to oven and cook for another 5-8 minutes, or until golden brown.
  9. Remove from oven and serve hot!

Adapted from Pillsbury.

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