In a glass jar, whisk together the soy sauce, pineapple juice, brown sugar, ketchup, shallots, garlic, ginger, and a pinch of chili flakes. Pour 1/3 of the sauce over the chicken and let sit 15 minutes or up to overnight in the fridge. Meanwhile, make the salsa: combine all ingredients in bowl. Heat the oil in a large skillet over medium-high heat. Add the chicken, cook 5 minutes until cooked through on both sides. Reduce the heat to medium and pour in the remaining soy sauce mix. Cook until the sauce glazes the chicken and begins to caramelize, about 5 minutes. Remove from the heat and stir in the cilantro. Serve the chicken over rice and spoon the salsa over the chicken. Sprinkle on the diced avocado and a squeeze of lime.