Use a heavy, 12-inch frying pan. Heat the pan over medium-high heat for about one minute. Add 1 teaspoon of ghee or oil and distribute it evenly using a spatula. Add the zucchini in a single-layer, cut-side facing down. Allow to brown slightly, then turn the pieces over to cook on both cut sides. Take care to just barely cook through; this should take only 4-5 minutes. Remove the zucchini to a plate and set aside.
With the heat still set at medium-high, add the onion and spread into one even layer. Add a bit of ghee or oil if needed, but there should be enough in the pan so they will not stick. Cook the onion until brown at the edges but are still barely cooked through, remove from the pan to the plate along with the zucchini.
Return the pan to the medium-high heat and wait about one minute to assure the pan is hot. Add the chicken pieces all at once to the hot pan and begin spreading in into one layer as quickly as possible. Once the chicken is in one layer, leave it alone to brown; about 5 minutes. Flip the pieces of chicken over and spread them back into a single layer. Add the curry powder and cook another 5 minutes until the chicken is nearly done. Add the cherry tomatoes, cooked zucchini, and onions to the pan with the chicken and stir to combine everything. Cook another 3 or 4 minutes to ensure the chicken is thoroughly cooked and the vegetables are hot. Ideally the zucchini will retain a bit of crunch when bitten.
Remove to a serving dish. Sprinkle liberally with chopped cilantro and/or sliced green onions.
