Celery Root and Leek Potato Cakes with Mushroom Gravy

For the potato cakes:
3 large, starchy potatoes
2 leeks, sliced thinly (white and light green parts only)
1 carrot, sliced thinly
1 celery root, chopped into thin strips about 1 inch long
2 tb butter
3 cloves garlic
5 sage leaves, sliced into thin strips
2 beaten eggs
1 tb fresh parsley, chopped
1 cup or more panko bread crumbs
olive oil for pan frying
salt and pepper to taste

For the mushroom gravy:
3 tb butter
2 tb flour
1 cup vegetable stock
3 small shallots, sliced thinly
2 cloves garlic
1 pound crimini mushrooms
5 morel mushrooms, hydrated and chopped
4 sage leaves, sliced into thin strips
leaves from 1 sprig of thyme
1 cup dry white wine
salt and pepper to taste

Potato Cakes:
Boil potatoes (or use leftover mashed potatoes, as long as they don't contain too much milk or other liquid). Meanwhile, melt butter in a heavy bottom pan and saute the leeks, carrots, and celery root over medium heat until the vegetables begin to soften. Add the garlic and sage and continue to saute until vegetables are cooked through. Add cooked potatoes to the celery root mixture and puree. Season to taste. Remove the puree from the heat and allow it to cool.

Once cooled, stir in parsley and beaten eggs. Then, drop large spoonfuls of the pureed potato mixture onto the bread crumbs, and coat. Form into cakes and set each one carefully onto a hot, olive-oil-coated-pan. Cook each side for about 3 or 4 minutes or until golden brown.

Gravy:
Make a roux with 2 tb of the butter, flour, and vegetable stock. Meanwhile saute shallots, garlic, sage and thyme in the remaining butter until the shallots are soft and translucent. Add the whole criminis and the morels and cook until they begin to release some of their liquid and soften. Pour in white wine and continue cooking. After a few minutes, pour the roux into the mushroom mixture and continue cooking until the liquid has thickened sufficiently and the mushrooms are cooked. Season to taste. Set some whole mushrooms aside, then puree the rest of the mixture. Return the whole mushrooms to the gravy, pour onto plates and serve with potato cakes.