Cut chicken breasts into a large bite-sized dice.

In a bowl, whisk together soy, mirin, corn starch, and baking soda. Add chicken chunks and stir to coat.

Marinate for 20 minutes.

Into a bowl, whisk together 400g ap flour, salt, baking soda and corn starch.

In a second bowl, add about 1/4 of the dry breading mixture. To that small portion of dry breader, whisk in water, a little at a time, until you're left with a loose pancake batter texture.

Into the bowl which the dry flour mixture, add about 1/4c of the wet breading slurry you just made. Mix and crumble the wet into the dry, creating a dry crumbly texture.

Grab a third bowl and fill it with 2-3 cups of AP flour. Add in the marinated chicken pieces. Mix to coat well on all sides.

Shake off as much of the ap flour mixture from the chicken as possible, then add chicken into the wet breading slurry. Toss to coat well. Now move pieces of wet battered chicken into the craggy dry breader mix. Mix to coat well.

Transfer chicken pieces to a tray.

Preheat a large heavy bottomed pot over medium-high heat with about 2qt of neutral oil (or about 2-3"/5-8cm of oil, leaving plenty of room at the top of your pot so oil doesn't boil over when you add chicken) for 10 min or until oil reaches a temp of 300F/150C.

Gently lower breaded chicken into the oil (use a spider to avoid splashing oil).

Fry for 4-5 min at 300F/150C. After 4-5 min or when nuggets are a light blonde golden color, remove from oil and transfer to a wire rack to drain.

Increase heat under oil pot to medium high to increase oil temp to 350F/175C.

Carefully lower the once-fried nuggets back into the oil to cook for about another 90 seconds or until they've taken on a nice golden brown color.

Transfer onto a wire rack and keep warm in a low oven while you make your orange chicken sauce.

To make the sauce, heat a generous squeeze of neutral oil in a large nonstick pan over medium high heat.

Into that pan, add ginger, garlic, and scallions and cook, stirring often, for about a minute until fragrant.

Whisk together chicken stock, mirin, soy sauce, sesame oil, sugar, rice vin, orange zest and juice and corn starch. Add sauce to pan with ginger/garlic/scallion mixture along with a pinch of chile flakes. Bring to a simmer and reduce sauce by about half - about 2 minutes.

After reducing, check the consistency of sauce. If it's not thick enough to leave a trail when you run a spoon through it, stir in a splash of corn starch slurry. Bring it back up to a boil and check the consistency again.

Add cooked nuggets into pan with the reduced sauce. Gently toss to coat, careful not to over work to loosen the breading.

Serve over rice and top with a pinch of sesame seeds and chile flakes.