To make chicken: In a shallow dish, combine the soy sauce and water. Add the chicken and marinate for at least 10 - 15 minutes at room temperature or up to a few hours in the refrigerator.
Place the flour on a plate. Remove the chicken from the marinade and roll the pieces around in the flour until all sides are coated.
In a large skillet, melt the coconut oil over medium heat. Add the chicken and cook until golden brown all over and cooked through, 6 - 8 minutes. Remove the chicken to a plate, leaving the flavorful bits in the pan.
To make the sauce: In the same pan over medium heat, cook the garlic, ginger, and pepper flakes for 30 to 60 seconds, then whisk in the vinegar, honey, soy sauce, and water and bring to a boil. Cook, scraping up the browned bits in the bottom of the pan, until the liquid begins to thicken, 2 to 3 minutes. Add the chicken, stir to coat it in the sauce, and serve warm.