1. Peel and mince onion. Shred chicken.
2. Heat the stock in a saucepan and reduce the heat to low to keep the stock hot.
3. Add the olive oil to a deep-sided skillet or sauté pan and set the heat to medium. Sauté the onion and garlic with sea salt until soft.
4. Add the rice and cook, stirring, for about 2 minutes.
5. Add white wine to the rice and stir. When the liquid has completely absorbed, begin adding the broth, one cup at a time. Do not stop stirring.
6. Repeat this process until you've used all (or most of) the broth and the rice is tender and creamy-looking, but still al dente—about 15–20 minutes total.
7. During cooking, check and adjust the heat, as needed, to maintain a steady simmer.
8. Add chicken to the risotto. Add sea salt and pepper to taste. Continue to cook until the ingredients are hot and well-combined.
9. Use your hands to shred spinach; add and continue cooking until the spinach is just wilted to bright green. Serve.