PREHEAT oven to 375°F. Add Macaroni to large saucepan of boiling water; cook 6 min. or until tender. Drain. Stir in milk and Cheese Sauce Mix.

POUR into greased 8-inch square baking dish; top with tomatoes. Mix cracker crumbs and butter; sprinkle over tomatoes.

BAKE 15 min. or until casserole is heated through and topping is golden brown.