-
1
Preheat the oven to 300 degrees.
-
2
Peel and cut the potatoes into rectangular shapes, about 3 by 1 1/2 inches.
-
3
Using a mandoline, a vegetable slicer or a sharp kitchen knife, slice each potato rectangle into 5 slices.
-
4
Line a cookie sheet with parchment paper and brush the parchment with the melted butter.
-
5
Spread out the potato slices on a cookie sheet.
-
6
Butter another piece of parchment paper and place, buttered side down, on the potatoes.
-
7
Cook in the oven until the potatoes are soft, about 10 to 15 minutes.
-
8
Chop all the mushrooms.
-
9
Heat 1 tablespoon of the butter in a saute pan and add the mushrooms.
-
10
Cook over medium-low heat until they are soft.
-
11
Add the finely chopped shallots and cook for 2 minutes more, or until the shallots are translucent.
-
12
In a medium-sized saucepan, melt 2 tablespoons of butter.
-
13
Add the diced celery, leeks, shallots and onion.
-
14
Saute for about 5 minutes.
-
15
Add the wine and, over high heat, reduce the liquid until it almost totally evaporates.
-
16
Add 1 cup of water, the garlic, thyme and lemon juice and reduce it by a fourth.
-
17
There should be 6 ounces of liquid.
-
18
Strain through a sieve, pressing on the vegetables to release the juices.
-
19
While the liquid is hot, pour it into a blender.
-
20
Whir the liquid, adding 8 ounces of butter tablespoon by tablespoon.
-
21
Season the sauce with salt and pepper to taste.
-
22
Pour the broth back into the pan and stir in the chopped parsley and diced tomatoes.
-
23
To serve, alternate slices of potato with mushrooms.
-
24
Spoon the celery sauce over the potatoes and serve.
