Combine all ingredients except flour and milk into a 6-quart slow cooker; stir to combine. Cover and cook on low for 4 hours.
Remove chicken; shred and place in the refrigerator.
Whisk together flour and milk in a small bowl; pour into chili and stir to combine.
Cover; cook on high for 30 minutes, stir shredded chicken back into chili, and serve with toppings. Taste before adding any more salt & pepper.
*This is a small batch, making just over 4 cups. Feel free to double the recipe if serving more than about 3 people.**This recipe can also be made on the stovetop. Cook shallot until tender and then add in other ingredients. Use cooked, shredded chicken. Rotisserie chicken works well. Mix milk and flour and add that too. Simmer everything together over low heat for about 5 minutes. Remove from heat and serve.