In a slow cooker or crockpot, add carrots, celery, mushrooms, chicken, garlic, jalapenos, oregano, basil, barley, chicken stock and salt. Stir well, and cook on high for 3-4 hours or low for 7-8 hours.
In a bowl, whisk together flour and milk, and once the soup is cooked, mix in the flour and milk mixture. Cook on high for 20 minutes
Add spinach to the slow cooker and mix well. Turn off the slow cooker, and let the soup sit for ten minutes. Top with bacon and serve hot!
Slow cooker: This is a slow cooker recipe. If you don't have a slow cooker you can make this soup in a crockpot over the stove.
Spinach: Spinach does not take long to cook so remember to only add it at the very end.
Storage: This soup can be frozen for upto a month but if you are planning to do that, do not add the spinach. It would case the dish to become bitter. Add spinach after defrosting and reheating as per the recipe.