Place all ingredients ina a slow cooker except the black beans.
Cook on high covered 5 hours until vegetables are softened. At the last hour, add the black beans and stir the chili.
Cover and cook 1 hour more until fragrant. Transfer to a bowl and serve immediately with 1-2 tablespoons of Greek yogurt or coconut yogurt on stirred mixed in.
Notes
Cut the butternut and sweet potatoes into uniform ½” pieces so that they all cook at the same rate.
Rinse the beans to reduce the amount of sodium and cut back on the gas-causing component in the bean liquid.
For rich, bold flavor, add the spices at the beginning of the cooking process, then taste the chili before serving to adjust to your tastes.