Place the water and vinegar into a small saucepan. Bring to a small boil, then add in the sugar and salt and stir until dissolved. Remove from the heat, sprinkle with the red pepper flakes if desired, then place into the refrigerator to chill while you make the okra.Combine the almond or soy milk with the vinegar and baking powder in a medium-sized glass pyrex casserole dish or large prep bowl. Allow it to sit undisturbed for about 10 minutes.
To make the okra
Wash it, pat dry, then add it to the milk and vinegar mixture. Allow to marinate for 30 minutes, tossing the okra around every 10 minutes or so to ensure all pieces are coated.
Pour several inches of oil into a medium-sized dutch oven and warm over medium-high heat. After about 10 minutes, test the oil by throwing a pinch of batter in it. If it sizzles immediately, you are ready to fry. (You can also insert a thermometer into the oil and begin frying once it reaches 350 degrees.)
While you are waiting for your oil to heat up, place the cornstarch and potato flour into a large shallow bowl, and stir to combine.
In a separate bowl, whisk together the Ener-G and water.
Remove about a quarter of the okra from the milk/vinegar mixture and place it into the Ener-G mixture. Toss to coat, then shake off any excess, then transfer it to the flour mixture. Dry your hands off, then toss the okra in the flour mixture to coat, tapping of any extra.
Gently drop the okra pieces one by one into the oil. Allow to fry for a few minutes, until golden brown. Remove with chopsticks or tongs and place on paper towels, sprinkling immediately with salt. Repeat the process for the next three batches.