In 1-cup glass measuring cup, mix milk and whipping cream. In 4-quart or larger Dutch oven, melt butter over low heat. With whisk, stir in flour and remaining 1/4 teaspoon salt until smooth. Increase heat to medium; cook, stirring constantly, until mixture is smooth and bubbly. Gradually stir in milk mixture. Increase heat to medium-high; heat to boiling, stirring constantly. Boil and stir 1 minute; reduce heat to medium. Stir in cheese. Cook until melted, stirring occasionally. Remove from heat. Stir in cauliflower, green onions and green chiles. Pour into baking dish.