Greek Beef Pitas

Ingredients

• 1 pound lean ground beef (90% lean)
• 1 small onion, chopped
• 3 garlic cloves, minced
• 1 teaspoon dried oregano
• 3/4 teaspoon salt, divided
• 1 cup reduced-fat plain Greek yogurt
• 1 medium tomato, chopped
• 1/2 cup chopped peeled cucumber
• 1 teaspoon dill weed
• 4 whole pita breads, warmed
• Additional chopped tomatoes and cucumber, optional