Sautéed Jerusalem Artichokes

2 Tbsp olive or sunflower oil
1 onion, diced
1 1/2 lbs jerusalem artichokes, scrubbed and sliced 1/4 inch thick (about 5 cups)
juice of 1/2 lemon
salt and pepper

Heat the oil in a large skillet over medium-high heat. Add the onion and the jerusalem artichokes and sauté until the jerusalem artichokes are crispy on the outside and soft on the inside, 5-8 minutes.Season to taste with salt and pepper.Sprinkle with lemon juice and serve hot.