Combine first 3 ingredients; stir well. combine half of lemon juice mixture and shrimp in a 9-inch glass pieplate; toss well. Cover and marinate in refrigerator 1 hour, stirring occastionally. Combine mushroom slices and remaining lemon juice mixture; toss well. Cover and set mixture aside. Arrange shrimp spoke-fashion in a single layer with yhickest portion toward outside of pieplate. Cover with heavy-duty plastic wrap and vent. Microwave at HIGH 2 minutes to 2 minutes 20 seconds or until shrimp is done, rearrange shrimp and rotating pieplate a halfturn after a minute. Drain shrimp and reserve marinade. Add water and next 4 ingredients to reserved marinade, stirring with whisk. Add shrimp; toss well. Thread 1 mushroom slice and 1 shrimp onto each of 24 wooden picks. Yeild 24 appetizers (about 15 calories each).