Clean the Jerusalem artichoke, dab off the moisture and cut into 1 cm thick slices. Put the oil in a coated pan and fry the Jerusalem artichoke slices until golden brown on both sides, then continue frying over medium to low heat. After 15 minutes, pour the oil into a shallow casserole dish and sprinkle with chopped walnuts and garlic, season with salt and pepper. Cook in the oven for another 10 minutes. Season to taste and serve.
Variations:
Add 2 tablespoons of sage, walnuts and garlic to the roast. Then continue as above.
Fry thicker slices in a pan for 10 to 15 minutes with salt and pepper until golden brown. Then add sliced garlic (only) for the last 5 minutes. Season with salt, pepper and lemon juice.