Heat a tablespoon of olive oil in a large pot over medium heat.

Add the diced onion and minced garlic to the pot, and sauté until the onion is translucent, about 3 to 5 minutes.

Cut the chicken thighs into bite-sized pieces and season with salt and pepper. Add the chicken to the pot and cook until browned on all sides.

Toss in the chopped red bell pepper and cherry tomatoes, and cook for another 3 minutes.

Pour in the chicken broth and stir in the cooked cannellini beans, dried Italian herbs, and more salt and pepper if desired. Bring to a simmer.

Let it simmer for about 20 minutes, stirring occasionally, until the chicken is cooked through and the flavors meld.

Finally, add the spinach and let it wilt for about 2 minutes.

Taste and adjust seasoning if necessary before serving.