1. Pat halibut steaks dry; set aside. Place 1 package vegetables in greased Crock-Pot. Combine flour, sugar, and salt.
2. In saucepan. melt butter; stir in flour mixture. When well blended, add wine and 1/2 and 1/2 and cook over medium heat until thickened, stirring constantly. Allow sauce to boil 1 minute while stirring.
3. Pour half the sauce over vegetables in Crock-Pot. Add half of halibut steaks and remaining package of vegetables. Pour remaining half of sauce over vegetables and top with last of halibut.
4. Cover and cook on high setting for 1 hour, then on low 2 hours. Transfer halibut to serving platter; garnish with lemon. Stir sauce and vegetables; serve separately in a vegetable dish.