Cook linguine according to package directions; drain and set aside.
Remove and discard green tops from leeks. Cut white portions in half lengthwise, and cut into 1/4-inch slices.
Sauté leek and bell pepper in hot oil in a large skillet 5 to 6 minutes or until tender. Stir in tomatoes, salt, and pepper; cook over medium heat, stirring occasionally, 2 minutes. Stir in linguine and parsley; cook over medium-high heat, stirring occasionally, until thoroughly heated. Sprinkle with cheese. Garnish, if desired. Serve immediately.
