PREHEAT oven to 350°F. Place half of the cream cheese and the onions in small bowl. Beat with electric mixer on medium speed until well blended; set aside for later use.
PLACE remaining cream cheese, the cheddar cheese, Monterey Jack cheese, green chilies and cumin in large bowl. Beat with electric mixer on medium speed until well blended. Add eggs, one at a time, beating well after each addition; set aside. Heat oil in medium skillet. Add tortillas; cook just until warmed. Spoon 2 Tbsp. of the cheese mixture onto each tortilla; roll up. Place, seam-sides down, in 13x9-inch baking dish; top with the enchilada sauce.
BAKE 20 min. or until heated through. Top with the reserved cream cheese mixture and the olives.