HEAT oven to 350ºF.
HEAT dressing in large nonstick skillet on medium-high heat. Add chicken; cook 6 min. or until done, stirring occasionally. Remove from heat. Add rice and zest; mix lightly.
SPREAD tortillas with hummus; top with chicken mixture, cheese and spinach. Fold in opposite sides of each tortilla, then roll up burrito-style. Place, seam-sides down, in single layer in casserole.
BAKE 20 min. or until heated through; top with yogurt and tomatoes.