In a small bowl, whisk in the broth, coconut aminos, vinegar, fish sauce, black pepper and ground ginger. Set aside until ready to use.
Place the chicken breasts on a cutting board and cover with parchment paper. Use a meat mallet or the bottom of a skillet to pound the chicken until it is an even thickness. Discard the parchment, then cut the chicken into 1-inch cubes.
Place the cubed chicken in a medium bowl with 2 teaspoons of the oil, salt, and pepper. Toss to evenly coat, then add the flour and toss again.
In a large, nonstick skillet over medium-high heat, heat the remaining ΒΌ cup oil. When the oil is very hot but not smoking, add the chicken to the skillet in a single layer (you may need to do this in 2 batches). Cook the chicken until golden brown and cooked through, 3 to 4 minutes per side. Transfer chicken to a plate and set aside.
Add the celery and onion to the same skillet and cook over medium-high heat, stirring occasionally, until the vegetables are slightly tender, about 4 minutes. Add the garlic and cook until fragrant, being careful not to burn, 1 minute.
Return the chicken to the skillet with the sauce and bring to a boil. Reduce to a simmer and cook for about 5 minutes, until the sauce is thick and coats the chicken and vegetables.
Remove the pan from the heat and season with salt to taste.