In 4-quart Dutch oven, melt butter over medium heat. Cook onion and sweet potato in butter 10 to 12 minutes, stirring occasionally, until tender. Add garlic and curry powder; cook 1 minute. Stir in flour; cook and stir 1 minute. Gradually add milk and broth. Heat to boiling; reduce heat to medium-low. Cook 5 minutes, stirring constantly, until thickened. Stir in chicken, peas, salt and cilantro. Spoon mixture into pie plate.