Ingredients
- 4 tablespoons unsalted butter
- 1/2 teaspoon kosher salt
- 1/2 teaspoon pepper
- 1 tablespoon Worcestershire sauce
- 1 teaspoon fresh thyme, chopped (plus more for garnish)
- 1/2 cup beef broth
- 8 cups zucchini, seeded and sliced thin (about 2 medium)
- 2 large yellow onions, sliced thinly
- 2 teaspoons granulated sugar
- 2 cups gruyere cheese, shredded and divided
Instructions
- Preheat your oven to 375°F (190°C). Grease a 9×13-inch baking dish or a similar-sized casserole dish.
- In a large skillet over medium heat, melt the butter. Add the sliced onions, kosher salt, pepper, and sugar. Cook, stirring frequently, until the onions are caramelized and golden brown, about 15-20 minutes.
- Stir in the Worcestershire sauce, fresh thyme, and beef broth. Add the sliced zucchini to the skillet and mix well. Cook for an additional 5-7 minutes until the zucchini is slightly softened.
- Transfer half of the zucchini and onion mixture to the prepared baking dish. Sprinkle with 1 cup of shredded gruyere cheese. Add the remaining zucchini and onion mixture on top, followed by the remaining 1 cup of cheese.
- Cover the dish with aluminum foil and bake in the preheated oven for 25 minutes. Remove the foil and bake for an additional 15-20 minutes, or until the cheese is bubbly and golden brown.
- Remove from the oven and let it cool for a few minutes. Garnish with additional fresh thyme if desired. Serve warm.
Notes
For extra flavor, try adding some grated Parmesan cheese along with the gruyere. Ensure to slice the zucchini and onions thinly for even cooking.
- Prep Time: 15 minutes
- Cook Time: 45 minutes
- Category: Main Course
- Method: Baking
- Cuisine: French
- Diet: Vegetarian