To get a jump start, steam green beans, drain, and chill in a zip-top plastic bag.
Arrange green beans in a steamer basket over boiling water. Cover and steam 5 to 7 minutes. Plunge into ice water to stop the cooking process; drain.
Melt butter in a large skillet over medium heat; add shallots, and sauté 3 minutes or until tender. Add green beans, tomato, and next 3 ingredients. Cook 5 minutes or until thoroughly heated. Serve immediately.