Description
A comforting and savory vegetarian casserole combining caramelized French onions with hearty farro and lentils, baked to tender perfection and topped with melted gruyere cheese for a rich, cheesy finish.
Ingredients
Scale
Onions and Aromatics
- 2 lbs yellow onions (4 large or 5 medium), sliced
- 2 tablespoons unsalted butter
- 1 tablespoon olive oil
- Kosher salt and freshly ground black pepper, to taste
- 2 tablespoons dry sherry, vermouth, or white wine (optional)
- 2 cloves garlic, minced
Grains and Broth
- 1 1/2 cups dried farro
- 3/4 cup dried lentils (green Le Puy or brown Italian preferred)
- 6 cups vegetable broth + splashes more as needed
- A few sprigs of fresh thyme
Topping
- 2 cups coarsely grated gruyere cheese
Instructions
- Caramelize Onions: In a large, deep sauté pan (preferably ovenproof), heat the butter and olive oil over medium heat. Add the sliced onions and toss to coat thoroughly. Cover the pan and reduce heat to medium-low, allowing the onions to cook gently and begin softening over 15 to 20 minutes without stirring. Uncover, increase heat to medium-high, add 2 teaspoons kosher salt, and cook the onions uncovered, stirring every few minutes, until they are deeply browned, soft, and sweet—about 20 more minutes. Adjust heat to medium as needed to prevent burning and ensure any released moisture evaporates.
- Preheat Oven: Set your oven to 375°F (190°C) to prepare for baking the casserole.
- Assemble Casserole: Add minced garlic to the caramelized onions in the pan and cook while stirring for one minute. Pour in the optional sherry (or substitute) and cook until the liquid evaporates. Stir in farro and cook for 2 minutes, then add lentils, vegetable broth, and fresh thyme sprigs. Bring the mixture to a simmer and season with salt and freshly ground black pepper as needed. If your pan is not ovenproof, transfer the mixture to a casserole dish at this point.
- Bake the Casserole: Cover the pan or casserole dish and bake in the preheated oven for 40 to 50 minutes, stirring about halfway through to ensure even cooking. If the liquid is fully absorbed either halfway or at the end, add an additional 1/4 to 1/2 cup of vegetable broth to maintain a slightly loose, risotto-like consistency. Remove and discard the thyme stems when done.
- Finish with Gruyere: Sprinkle the grated gruyere cheese evenly over the top of the hot casserole and place under the broiler until the cheese is melted and golden brown. Serve immediately for a rich, cheesy finish.
Notes
- Using an ovenproof sauté pan allows you to go from stovetop caramelizing to oven baking without transferring the food.
- If you don’t have sherry or vermouth, white wine or water can be used, though the flavor will be less complex.
- Feel free to experiment with different types of lentils, but green Le Puy or brown lentils are recommended for texture.
- Add more broth during baking if the mixture becomes too dry; the goal is a creamy, slightly loose texture.
- Gruyere can be substituted with other melting cheeses like fontina or mozzarella for variation.
- Prep Time: 15 minutes
- Cook Time: 1 hour 15 minutes
- Category: Main Dish
- Method: Baking
- Cuisine: French
Keywords: French onion baked lentils, farro casserole, caramelized onions, vegetarian casserole, gruyere baked lentils, healthy lentil dish
