Tomato Salad With Mustard-Basil Dressing

Ingredients

• 1/2 cup plain nonfat yogurt
• 1 1/2 teaspoons dried basil
• 1 1/2 teaspoons prepared horseradish
• 1 teaspoon olive oil
• 1 teaspoon grated parmesan cheese
• 1/2 teaspoon red wine vinegar
• 1/4 teaspoon Dijon mustard
• 1/8 teaspoon sugar
• 1/8 teaspoon salt
• 1/8 teaspoon pepper
• 4 romaine lettuce leaves
• 2 large ripe tomatoes , chopped just before serving