Combine first 4 ingredients; stir well, and set aside. Coat a nonstick skillet with cooking spray; place over medium-high heat until hot. Add onion; saute 2 minutes. Add spinach; saute 1-1/2 minutes or until spinach begins to wilt. Stir in rice, feta cheese, 1-1/2 teaspoons dillweed, and 1-1/2 teaspoons chives, and set aside. Beat egg yolks in a bowl until thick and pale (about 5 minutes). Add milk; beat until well blended, and set aside. Beat egg whites (at room temperature) and salt until soft peaks form. Add the remaining dillweed, remaining chives, flour, and pepper, beating until stiff peaks form. Gently fold into egg yolk mixture. Coat a medium-size nonstick skillet with cooking spray, and place over medium heat until hot. Spread egg mixture evenly in skillet; top with spinach mixture. Cover, reduce heat to medium-low, and cook 10 minutes or until center is set. Carefully loosen omelet with a spatula, and fold in half; gently slide omelet onto a warm serving plate. Spoon tomato mixture over top. Yield: 2 servings. Per serving: 260 Calories; 8g Fat (28% calories from fat); 14g Protein; 32g Carbohydrate; 222mg Cholesterol; 521mg Sodium Serving Ideas : Cut omelet in half; garnish with dillweed, if desired. Recipe by: Cooking Light, May/Jun 1993, page 90 Posted to MC-Recipe Digest V1 #393 by igor@digex.net on Jan 28, 1997.