Overnight white bean barley soup

The day *before*, bring 1 cup dried navy beans to boil, then let sit overnight.

In the morning, put beans in slow-cooker and add 6 cups water, 1/2 cup barley, garlic, ~3 carrots, ~3 celery, 1/2 onion, can of tomatoes, half a bag of spinach. Dried porcini mushrooms, if you have them, make the dish.