Bring tomatoes, pasta and water to boil in large saucepan; stir. Cover; simmer on medium-low heat 10 min. or just until pasta is tender.
Add half the spinach; simmer, about 2 minutes or just until wilted. Stir. Add the remaining spinach.
Toss in chicken cubes and cook about 3-4 minutes, stirring occasinally. Top with cheese and serve.