Cut the chicken thighs into bite-sized pieces.
Chop the onion, zucchini, carrot, and celery into pieces for easy eating.
Add olive oil to a pot and sauté the chicken thighs.
When the chicken is half-cooked, add all the prepared vegetables and continue to sauté.
Pour in the canned tomatoes and water, then bring to a boil.
Season with salt and pepper, and simmer on low heat for 20 minutes.