Combine water, chicken, carrot, and sliced onion in a large saucepan. Bring to a boil; cover, reduce heat, and simmer 30 minutes. Remove chicken from broth; cool. Bone chicken, and cut meat into 1" pieces. Set aside. Strain broth, saving 3/4 cup. Coat a large nonstick skillet with cooking spray; place over med-hi heat until hot. Add chopped onion, and saute until tender. Gradually add 1/4 cup flour and tarragon, stirring well. Gradually stir in 3/4 cup skim milk, yogurt, wine, and reserved 3/4 c chicken broth. Cook, stirring constantly, until mixture is thickened and bubbly. Stir in peas, pimento, and reserved chicken. Set aside, and keep warm. Combine remaining 1 cup flour and salt, stirring well. Add eggs and remaining 1 cup skim milk; beat with a wire whisk until well blended. Spoon mixture evenly into six 6-oz custard cups that have been coated with Pam. Place 4" apart on a baking sheet. Bake at 400 deg F for 45-50 minutes or till golden brown. Break open each popover. Spoon 1/2 cup chicken mixture over each popover. Serve immediately. PER SERVING: 276 calories, 25.4 g protein, 3.9 g fat, 33.1 g carbohydrates, 133 g cholesterol, 2.2 mg iron, 236 mg sodium, 162 mg calcium.