Greek-Style Lamb Burgers

Bahan-bahan (6 porsi)

• 1 slice white bread, (crust removed and cut into ¼-in (6-cm) pieces)
• 2 tablespoons milk
• ¼ cup finely chopped shallots, (from 1 to 2 shallots)
• 2 cloves garlic, (minced)
• 3 tablespoons finely chopped fresh mint
• 1 teaspoon dried oregano
• ¾ teaspoon salt
• ½ teaspoon freshly ground black pepper
• 1½ lbs ground lamb ((not lean; 80/20 beef may be substituted))
• 6 pita bread rounds, (or use hamburger buns (see note))
• 1 small head iceberg lettuce, (shredded)
• 2 tomatoes, (thinly sliced)
• 1 red onion, (thinly sliced)
• 6 oz crumbled feta cheese
• Tzatziki sauce