Cut the chicken into bite-sized pieces, about 1 inch thick.

Preheat 2 inches of oil in a large pot or deep skillet over medium heat.

In a small bowl, beat the egg with the sunflower oil, salt, and pepper until combined.

In a separate bowl, mix together the cornstarch and all-purpose flour.

Dip each piece of chicken into the beaten egg mixture, then dredge it in the flour and cornstarch mix. Shake off any excess flour.

Deep fry the chicken in batches, in oil heated to 350°F, until crispy and golden brown, and the internal temperature reaches 165°F.

Transfer the fried chicken to a large plate lined with paper towels to drain the excess oil.

In a saucepan, combine the white distilled vinegar, cane sugar, water, soy sauce, crushed red pepper flakes, garlic, zested ginger root, and orange juice concentrate. Bring to a boil over medium heat.

Reduce heat and simmer for 1-2 minutes until the sauce thickens to your liking.

Add the fried chicken pieces to the sauce and toss gently to coat evenly.

Transfer the coated orange chicken to a serving dish. Enjoy it hot with your choice of sides!