Spinach Apple Salad

2 Tablespoons cider vinegar
2 Tablespoons vegetable oil
1/4 teaspoon salt
1/4 teaspoon sugar
1 cup diced unpeeled apple
1/4 cup chopped sweet onion
1/4 cup raisins
1/8 cup walnuts (optional) my added touch
2 cups torn fresh spinach
2 cups torn romaine
In a small bowl, combine vinegar, oil, salt and sugar; mix well. Add apple, onion, walnuts, and raisins; toss lightly to coat. Cover and let stand for 10 minutes or overnight. Just before serving, combine spinach and romaine in a large salad bowl; add dressing and toss. Yield: 4-6 servings