Mixed Roots Gratin

5 tbsp olive oil
1 med onion, chopped
8 oz chantrelles, oyster, or shiitake mushrooms, sliced
4 cloves garlic, minced
salt & pepper
1c dry white wine
1 1/2 lb roots (incl potatoes, rutabagas, parsnips, turnips), peeled and thinly sliced
6 oz grated cheddar or gruyere cheese

 Lightly oil a deep-sided baking dish. Heat oven to 400F. Heat 4 tbsp olive oil in skillet; add onions and mushrooms and saute over high heat 5-6 minutes. Season to taste with salt and pepper. Add half the wine and boil it off, stirring it well. Spoon a thin layer of the mixture into baking dish. Arrange root slices over mushroom layer, alternating and overlapping them slightly. Sprinkle with a little garlic, moisten with wine and a few drops of olive oil and top with grated cheese. Season lightly. Repeat the process, reserving some cheese to finish. Bake 35 min or until soft and golden. Four servings.