- 2 lb assorted fresh wild mushrooms brushed clean and sliced
- ½ cup dry Porcini mushrooms
- 1 large Spanish onion sliced into thin quarter-rounds
- 1 cup sour cream
- 1 cup whole milk warmed and kept hot
- pinch of nutmeg
- 1 tbsp all-purpose flour
- pinch of fennel seeds
- ½ lb Gruyere cheese shredded
- 3 tbsp unsalted butter
- 4 tbsp vegetable oil
- salt and pepper to taste
- Add enough boiling water to dry Porcini to barely cover them. Cover the container and let stand for at least 30 minutes.
- Make bechamel sauce by warming 1 tbsp butter over very low heat; once the butter is completely melted and begins to bubble, quickly sift the flour over it. Stir the mixture with a wooden spoon constantly, taking care that the flour does not burn.
- Once the mixture has become a deep golden color, remove from heat and add milk in a thin stream, whisking vigorously to prevent clumps. Cover and let stand for 5 minutes.
- At the end of the 5-minute period, whisk lightly. The sauce should have thickened to a consistency of a rich cream. If too thick, whisk in a little more hot milk.
- Add nutmeg and season with salt. Cover and set aside.
- Warm 1 tbsp and 2 tbsp vegetable oil in a large, deep skillet. Add mushrooms and sauté on high heat, stirring, until the mushrooms are browned, about 10 minutes.
- Strain the liquid from the dry Porcini into the skillet; discard the dry mushrooms. Continue cooking, stirring from time to time, until the mushrooms have absorbed most of the liquid.
- Remove the mushrooms from the skillet and set aside. Wipe the skillet dry and return to heat; add 1 tbsp butter and 2 tbsp vegetable oil.
- Add the onions and sauté over low heat, stirring from time to time, until the onions have decreased in volume and caramelized evenly. (This takes anywhere from 45 minutes to 1 hour, so be patient!)
- Return the mushrooms to the skillet. Wisk together sour cream and béchamel sauce, and add the mixture to the skillet.
- Season with salt and pepper and add fennel seeds. Stir and cook, covered, over low heat for 15 minutes.
- Preheat the oven. Distribute the stew evenly among individual mini-crocks or ramekins (but mini-crocks are best).
- Top with Gruyere cheese and broil, uncovered, until the cheese has melted and formed a deep yellow crust with brownish blisters.
Julien is typically served as a hot appetizer dish.