Mini Lamb Burgers

Name: Mini Lamb Burgers
Ingredients: 1/2 English cucumber peeled, seeded, and grated (¾ cup); 1/2 cup plain yogurt preferably whole milk yogurt; 2 teaspoons fresh lemon juice; 2 teaspoons chopped fresh mint; 1 small garlic clove minced; Salt and pepper; 1- 1/2 lb. ground lamb; 1/2 small onion minced (¼ cup); 1/4 cup chopped fresh parsley; 2 teaspoons chopped fresh oregano or 1 teaspoon dried; 4 pita breads (6-inch); Iceberg lettuce for serving; 2 medium beefsteak tomatoes sliced, for serving