Rinse beans and cover with water. Soak overnight.
Rinse and drain beans and add to crockpot.
Cut sausage into 1 inch pieces and add to crockpot. Layer chicken thighs on top.
Saute onion, carrot and celery in the oil until just beginning to brown. Spread over meat in crockpot.
Sprinkle herbs over everything. Add can of tomatoes. Pour stock or water over. It should cover everything. If it doesn't, add a little more water.
Cook on high 5 hours or on low for 8 hours. Gently stir occasionally.
Serve with crusty bread or over rice.
You can use canned beans, but you'll need to reduce the liquid and cooking time.
This can also be made in the oven in a Dutch oven - 250°F for 3-4 hrs