Cook dumplings according to package directions, omitting salt and fat.
Meanwhile, heat olive oil in a large nonstick skillet over medium heat. Saut mushrooms 2 minutes or until soft.
Add garlic; saut 1 minute. Reduce heat to low; stir in Alfredo sauce and next 3 ingredients. Stir in spinach. Cook 3 minutes or until thoroughly heated and spinach wilts.