Green Beans and Radicchio with Parmesan

2 ? tablespoons olive oil
12 ounces green beans, trimmed
1 medium yellow onion, halved and thinly sliced
salt and pepper
2 cups ? inch strips of radicchio (about 6 ounces)
1 clove garlic, minced
1 tablespoon fresh lemon juice
Shavings of Parmesan cheese

Heat skillet over medium-high heat for one minute. Pour in two tablespoons of oil and swirl to coat.
As soon as the oil is hot (but not smoking) add green beans in an even layer. Scatter onion slices on to and season with salt and pepper. Let cook, undisturbed, about two minutes.
Add radicchio and saut?, stirring occasionally, until the radicchio has begun to wilt and brown and the beans are crisp tender.
Stir in garlic and cook about one minute more.
Transfer to bowl and drizzle with lemon juice and remaining oil. Season with salt and pepper and garnish with Parmesan shavings.