After the chicken is sliced into strips, about ¼ inch thick or so, spread them out and sprinkle with about ¾ teaspoon of salt, ¼ teaspoon of black pepper, and 1 teaspoon of curry powder, mix together.
Using a large non stick pan, heat 1½ tablespoons of oil on medium high heat, when hot but not smoking, add the chicken in a single layer and cook, stirring often to just lightly brown them, no need to cook all the way through, about 3 minutes. Remove from the pan and set aside.
Reduce the heat on the pan to medium and add the rest of the oil, and the onion and cook until softened and translucent, then stir in the garlic, ginger, and remaining curry powder and cook until fragrant, maybe a minute or so, stir often.
Whisk the cornstarch, sugar, and a pinch of salt into the broth then add the broth to the pan, bring to a boil then reduce to a simmer until the sauce is thickened, about 5 minutes. Return the chicken to the pan along with the peas and simmer until the chicken is cooked through, takes just a few minutes.
Remove the pan from the heat, stir in the yogurt and cilantro, taste and adjust seasoning with salt and pepper if desired.
Serve with steamed rice.