1. Heat oil in a medium saucepan over medium-high heat. Add onion; cook 5 minutes or until softened, stirring. Add garlic and thyme; cook 1 minute, stirring. Add beans, water, tomatoes, and broth. Increase heat to high until stew begins to bubble. Reduce heat; let simmer 5 minutes, breaking up tomatoes with a spoon. Add more water, if needed.
2. Add spinach, stirring until wilted. Add chicken; cook 2 minutes. Season with salt and pepper.