Festive Potato Salad

Ingredients

• 8 medium red potatoes, cooked and cubed
• 2 celery ribs with leaves, thinly sliced
• 2 green onions with tops, chopped
• 4 hard-boiled large eggs, chopped
• 1/2 cup chopped peeled cucumber
• 1/4 cup chopped sweet red pepper
• 1/4 cup chopped green pepper
• 1-1/4 cups mayonnaise
• 1/4 cup sour cream
• 1/4 cup plain yogurt
• 1 tablespoon each minced fresh basil, marjoram and dill or 1 teaspoon each dried basil, marjoram and dill weed
• 1 teaspoon sugar
• 1/2 teaspoon salt
• 1/2 teaspoon pepper
• 4 plum tomatoes, coarsely chopped
• 1 cup frozen peas, thawed
• 1 cup shredded cheddar cheese