Portobello Mushroom Gratin
I designed this portobello gratin as sort of a mix between my zucchini gratin and my bell pepper gratin with fennel and mushrooms. It's a robust blend of earthy flavors topped with the classic gratin cheese, Gruyere.
- Serves: 6 persons
- 4tablespoons butter
- 2leeks, diced
- 1celery root, chopped
- 3large portobello mushroom caps, diced
- 1tablespoon chopped fresh tarragon, divided
- 1tablespoon chopped fresh chives, divided
- 1cup panko bread crumbs
- 1cup grated Gruyere cheese
- 1½ tablespoons all-purpose flour
- ¾cup heavy cream
- 2tablespoons water, or as needed
Step 1Preheat the oven to 400 degrees F (200 degrees C).
Step 2Melt butter in a frying pan over medium heat. Add leeks and celery root and cook for 10 minutes. Add mushroom pieces, 1/2 of the tarragon, and 1/2 of the chives; continue cooking until mushrooms give off liquid, about 6 minutes more.
Step 3Meanwhile, combine bread crumbs and Gruyere cheese in a mixing bowl.
Step 4Add flour to the frying pan with the mushroom mixture. Add cream in a stream and stir until it becomes an even color, about 3 minutes. Add 1/2 of the bread crumb mixture and stir until cheese starts to melt, about 2 minutes. Turn off heat. Transfer mixture to a baking dish and top with remaining tarragon, chives, and bread crumb mixture. Add a small amount of water to moisten the mixture.
Step 5Bake in the preheated oven until the cheese is bubbly, about 10 minutes.
Step 6Use a spatula to scoop portions and serve immediately.