Ingredients

• 1 lb lean ground beef
• 1/2 small onion, minced
• 1/2 cup very finely crumbled feta cheese (measure after crumbling)
• 2 garlic cloves, minced
• 1 tablespoon extra virgin olive oil, plus more for baking dish
• 1 tablespoon dried oregano
• 4 teaspoons red wine vinegar
• 1/4 teaspoon salt (optional, it didn't need it)
• 1/4 teaspoon fresh ground black pepper
• 2 teaspoons all purpose Greek seasoning
• 1 large egg