Roast Beef and Potato Salad

Ingredients

• 2 cups cubed cooked roast beef
• 2 cups cubed peeled potatoes, cooked
• 1/2 cup chopped green pepper
• 1/2 cup thinly sliced celery
• 1/4 cup chopped onion
• 2 tablespoons chopped pimientos
• 1/3 cup vegetable oil
• 2 to 3 tablespoons vinegar
• 2 teaspoons prepared horseradish
• 1/2 teaspoon salt
• 1/8 teaspoon pepper
• Lettuce leaves
• 2 tablespoons chopped fresh parsley