1

Select a saucepan with a tight-fitting lid large enough to accommodate the green beans in a steamer basket. Fill the pan with water to a depth of 2 inches and then place the steamer basket in the pan. Cover and bring to a boil. When the water is boiling, add the green beans to the steamer basket, cover the pan, and steam the green beans until they are bright green and crisp- tender, 5 to 6 minutes. To test for doneness, pierce with a fork, or better yet, taste one. Remove from the heat, cover, and set aside.

2

While the beans are cooking, in a skillet over medium-high heat, melt the butter and swirl to coat the bottom of the pan. Add the onion and cook, stirring occasionally, for 1 minute. Add the mushrooms and cook, stirring occasionally, for 1 to 2 minutes. Add the tomato, lemon juice, salt, pepper, and Parmesan cheese and cook until the sauce is bubbling and the mushrooms and onion are tender, about 1 minute.

3

Transfer the beans to a warmed serving dish and add the tomato- mushroom sauce. Toss to coat evenly. Serve immediately.