Bifteki Recipe from Greece - Ground Beef, Feta, and Tomato

Ingredients

• 1 lb (454 g) ground beef
• 1/2 medium onion, finely diced
• 1 egg white or 2 tbsp plain yogurt
• 1/2 cup chopped fresh parsley or 0.5 tsp dried
• 3/4 tsp dried oregano
• 1/2 tsp cumin
• 1/2 tsp garlic salt
• 1/2 tsp black pepper
• 1 medium tomato
• 4 oz (113 g) feta cheese
• 1 tbsp olive oil
• parsley sprigs for garnish
• tzatziki