Marinate the chicken in a mixture of soy sauce, lemon juice, brown sugar, minced garlic, banana ketchup, Worcestershire sauce, and thai chili, if using, for at least 4 hours or overnight.
Thread the marinated chicken onto skewers.
Grill the chicken skewers over medium-high heat, turning occasionally, until cooked through and slightly charred, about 10-12 minutes.
Season with salt and pepper to taste.
