Bring a half-filled 4- to 6-quart pot of water to boil. Add frozen vegetables and return to a boil. Add noodles and cook, stirring occasionally, 3 minutes or until vegetables and noodles are tender. Drain in a colander.
Place pot over medium heat. Add water, the seasoning packets and cheese; stir until smooth. Add noodles, vegetables and pimientos; stir 3 minutes until hot and evenly coated.