Heat 1 Tbsp. oil in large nonstick skillet on medium heat.
Add half the chicken; cook 5 to 6 min. or until done, stirring frequently.
Remove chicken from skillet; cover to keep warm. Repeat with remaining oil and chicken, adding second batch of cooked chicken to first batch of cooked chicken.
Add macaroni, water, milk and butter to skillet; stir. Cook 8 to 10 min. or until macaroni is tender, stirring frequently.
Add cheese; stir until melted.
Add tomatoes and seasonings; cook 2 min. or until heated through, stirring frequently. Return chicken to skillet; stir to evenly cover chicken with tomato mixture. Cook 1 to 2 min. or until heated through, stirring frequently.