SPRAY large skillet with cooking spray. Add ham and mushrooms; cook on medium-high heat 5 min. or until mushrooms are tender, stirring occasionally.

ADD milk, water, Macaroni and thyme. Bring to boil. Reduce heat to low; cover.

SIMMER 5 min. stirring twice. Add peas; simmer 5 min. or until macaroni is tender. Stir in Cheese Sauce Mix until blended.