- 4 carrots, peeled and cut into 1/2-inch chunks
- 1 rutabaga, peeled and cut into 1/2-inch chunks
- 1/2 onion, chopped
- 1 1/2 cups chicken stock
- 1/4 cup butter, divided
- 1 tablespoon brown sugar
- 1 pinch freshly grated nutmeg
- 2 eggs, slightly beaten
- 1 tablespoon all-purpose flour, or as needed
- 2 tablespoons baking powder
- salt and ground black pepper to taste
- 1/2 cup finely chopped pecans
- Combine carrots, rutabaga, onion, chicken stock, 3 tablespoons butter, brown sugar, and nutmeg in a large saucepan; bring to a boil. Reduce heat, partially cover saucepan with a lid, and simmer, stirring occasionally, until vegetables are very tender, about 45 minutes.
- Transfer vegetables using a slotted spoon to a food processor or blender. Continue to cook remaining broth mixture in saucepan over high heat, stirring constantly, until liquid reduced to about 1 tablespoon, 2 to 3 minutes. Add reduced broth mixture to vegetables in food processor; blend until very smooth. Transfer mixture to a bowl and cool to room temperature.
- Stir eggs, flour, baking powder, salt, and pepper into pureed vegetable mixture until evenly combined; spoon into a buttered 6-cup casserole or souffle dish.
- Melt remaining 1 tablespoon butter in a saucepan over low heat; stir in pecans until fragrant and coated, 1 to 2 minutes. Spread buttered pecans around the edge the vegetable mixture, creating a border. Cover dish with plastic wrap and refrigerate, 8 hours to overnight.
- Bring vegetable mixture to room temperature, about 30 minutes before baking.
- Preheat oven to 350 degrees F (175 degrees C). Remove plastic wrap from casserole dish.
- Bake in the preheated oven until puffed, set in the middle, and golden brown, about 30 minutes.