HEAT oven to 450ºF.
WHISK eggs and milk until well blended. Stir in onions and tomatoes; pour into nonstick skillet sprayed with cooking spray. Cook on medium-low heat 5 min. or until eggs are set, stirring occasionally.
PLACE crust on baking sheet; top with egg mixture, VELVEETA and bacon.
BAKE 10 min. or until pizza is heated through and VELVEETA is melted.