Mashed Potatoes with Bacon, Onion and Celery

3 medium potatoes, peeled and cut into 1/2" cubes. 2 stalks celery, chopped. 4 green onions, chopped. 1/4 c water. 1/4 t pepper. 2 1/2 c milk. 1/4 c flour. 1 t onion salt. Add potatoes, celery, onions, water and pepper. Cover and microwave again on high for 10-12 minutes until vegetables are tender, stirring after 5 minutes. Combine 1/2 c milk and flour, stirring well. Stir into potato mixture. Add remaining milk and onion salt and microwave uncovered on high for 7-10 minutes until just thickened, stirring twice. Makes 2 quarts.