Shaker Bean Soup

Ingredients

• 1 lb. dry Great Northern beans
• water
• 1 meaty ham bone or 2 ham hocks
• 1 large onion, chopped
• 3 celery stalks, diced
• 2 carrots, shredded
• salt to taste
• 1/2 tsp. pepper
• 1 1/2 tsp. dry thyme
• 1 (28 oz.) can crushed tomato puree
• 2 Tbsp. brown sugar
• 1 1/2 c. finely shredded fresh spinach leaves