Kelaguen Mannok (Guam-Style Chicken Salad)

Ingredients

• 2 cups soy sauce
• 1 1/2 cups cane vinegar available from Exe's Asian Market
• 1 teaspoon ground black pepper freshly
• 1 yellow onion small, thinly sliced, plus 1 cup finely chopped
• 2 1/2 pounds boneless, skinless chicken thighs
• 4 cups scallions thinly sliced
• 1 1/2 cups grated coconut unsweetened
• 1/4 cup fresh lemon juice
• 8 Thai bird chiles stemmed and thinly sliced
• pita Toasted, for serving