In a slow cooker combine first 9 ingredients, mix well. Cover and cook on low 8 hours or until meat is tender. Drain through a colander , reserving juice as a dipping sauce, if desired.
Melt margarine add minced garlic, stir. Slice rolls, and brush each slice with margarine mixture. Toast in broiler until golden brown. If desired, spread with mayo. Place cooked venison chunks on rolls and serve warm with dipping sauce, if desired.