In a large pan, cook onions in oil until beginning to brown. Add garlic for the last 2 minutes.
Add tomatoes and cook for 2-3 minutes. Add chicken, mixing to cover. Cook uncovered, stiffing frequently.
Add spices and salt, increase heat to medium high and cover, cooking for about 20 minutes.
Add carrots, lower the heat to medium and continue to cook, covered (5 minutes)
Add potato and zucchini and continue to cook, covered (10 – 15 minutes).
Add a bit more salt, and boiling water until just about covered and cook on low for 20-30 minutes.