Stir together 1/4 cup diced tomato and green chiles, chicken, cream cheese, and green onions. Stir together remaining diced tomato and green chiles and sour cream; set aside.
Microwave tortillas at HIGH 15 seconds or until warm.
Arrange chicken mixture evenly down center of tortillas; roll up, and place, seam side down, in a lightly greased 13- x 9-inch baking dish.
Bake, covered, at 350° for 30 minutes. Pour sour cream mixture over enchiladas; top with cheese. Bake 10 more minutes; let stand 15 minutes.