Penne with Sausage, Radicchio, and Green Beans

In large saucepot over high heat, heat 6 quarts water to boiling. Trim ends from green beans; cut each bean crosswise in half. Add green beans to boiling water and cook 5 to 10 minutes, until beans are just tender-crisp. With slotted spoon, remove beans to bowl. In boiling water in saucepot, cook penne as label directs but do not use salt in water. Meanwhile, in covered nonstick 12-inch skillet over high heat, in 1/4 cup boiling water, cook sausages 5 minutes. Remove cover; reduce heat to medium-high and cook sausages until browned, about 5 minutes. With slotted spoon, remove sausages to cutting board and cut into 2-inch pieces. In drippings in skillet over medium-high heat, cook sausage pieces and onion until onion is golden and sausages are cooked through. Add radicchio to skillet and cook until wilted, about 5 minutes. Add diced tomatoes and tomato sauce; heat to boiling. Drain penne; return to saucepot. Add sausage mixture and green beans; toss to mix and heat through.