Submerge Artichokes In Lemon Juice And Water. Saute Onion And Garlic In Olive Oil For 4 Minutes. Add Lima Beans And Cook For 4 Minutes. Add Artichokes, Fennel, Salt, Pepper, And Sugar. Add Enough Water To Almost Cover. Bring To A Simmer, Cover And Simmer For 45 Minutes Or Until Vegetables Are Tender. Drain Reserving Cooking Liquid. In Another Pan, Heat Oil, Add Flour And Make A Thick Paste. Allow It To Change To A Golden Brown Color. Whisk In Lemon Juice And Then Cooking Liquid. Cook Over A Gentle Heat Until Sauce Has Thickened With No Lumps. Season With Salt And Pepper. Pour Sauce Over Vegetables And Serve.