Place 1/2 Teaspoon Saffron Threads In 1/4 Cup Hot Water And Set Aside For 30 - 40 Minutes To Steep.Peel And Cube 3 Medium Onions, (Approximately 3CUPS).Place In A Large Saucepan With 2 To 3 Tablespoons Water, Cover And Le Sweat Over Low Heat For 5 To 6 Minutes Until Transparent.Watch Carefully, D Not Let Burn.Peel And Cube 3 Medium Potatoes(Approximately 4 Cups)And Add Onions Along With 6 Cups Chicken Broth.Bring To A Simmer And Cook For 25 T 30 Minutes Until Tender.Put Through A Food Mill, Or Puree In A Food Process Or Blender.Return To Pan And Stir In 1 Cup Of Heavy Cream Together With Th Saffron Water.Heat Before Serving But Do Not Boil.Check For Seasoning, And Serve Topped With Additional Cream That Has Been Whipped And Thin Slices O Lemon.Serves 6.