2.
Add water to stuffing mix in large bowl; stir just until moistened. Let stand 5 min. Meanwhile, cover rimmed baking sheet with parchment; spray with cooking spray.
3.
Add chicken, egg and 1 tsp. curry powder to stuffing; mix just until blended. Roll into 20 meatballs, each about 1-1/2 inches in diameter; place on prepared baking sheet.
4.
Bake 16 to 18 min. or until done (160ºF).
5.
Meanwhile, cook onions in large nonstick skillet sprayed with cooking spray on medium heat 3 to 5 min. or until crisp-tender, stirring frequently. Add tomatoes, gravy and remaining curry powder; mix well. Simmer on medium-low heat 10 min., stirring occasionally. Pour into blender; cover with lid, then kitchen towel. Blend 1 min. or until smooth. Return sauce to skillet; cook 2 to 3 min. or until heated through, stirring frequently. Stir in sour cream.
6.
Add meatballs; stir until evenly coated. Cook 5 min., stirring occasionally.