Preheat oven to 400. Coat 8 6-oz. or 4 10-oz heatproof ramekins with cooking spray and place on baking sheet.
Equally divide green chiles, corn and scallions among the ramekins. Top each with cheese. Whisk milk, egg whites, eggs and salt in medium bowl until combined. Divide the egg mixture evvenly among the ramekins. Bake the mini casseroles until the tops begin to brown and the eggs are set, about 25 minutes for 6-oz ramekins, and 35 minutes for 10-oz ramekins.
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