Cut the chicken wings into drumettes and wingettes. It is up to you whether to discard the wingtips or not. I didn't; I simply cut off the ends of the wingtips.
Wipe the chicken dry with a kitchen towel then transfer to a bowl. Pour in the sour cream and mix well. Work the sour cream into the meat.
Add the salt, garlic powder, onion powder, ginger powder and half of the cayenne. Mix well. Cover the bowl and leave to marinate for at least an hour.
Make the glaze. Whisk together the Sriracha, honey and sesame seed oil.
Heat enough cooking oil in a wok or frying pan to reach a depth of three inches.
Whisk together the flour, starch and remaining cayenne. Dredge each piece of chicken in the mixture. Shake off the excess.
Fry the chicken wings in two batches until golden and crisp. Cook the drumettes together in the first batch and then the wingettes in the second batch. The drumettes take a little longer to cook than the wingettes so it makes more sense to cook similarly sized pieces in each batch. The drumettes take about eight minutes to cook; the wingettes, about seven minutes. Scoop out the chicken pieces as they cook and drain on a stack of paper towels.
Pour off the oil and wipe the frying pan or wok with paper towels.
Pour the glaze into the wok or frying pan and heat gently until the edges start to bubble. Turn off the heat. Add the cooked chicken to the glaze and toss to coat each piece completely. Add half of whatever seeds you're using and toss again.
Transfer the hot chicken wings to a serving platter, sprinkle in the rest of the seeds and the sliced scallions. Serve at once.