Slow Cooker Potato Soup

Ingredients

• 2 stalks celery, washed and diced
• 2 carrots, peeled and diced
• 1 yellow onion, peeled and diced
• 3 cloves garlic, minced
• 3 lb. Yukon gold potatoes, peeled and chopped into 1/2 to 3/4 inch chunks
• 1 t. Italian seasoning
• 1 1/4 t. salt
• 1/2 t. freshly ground black pepper
• 3 c. chicken broth
• 2 T. all-purpose flour
• 2 T. water
• 1/2 c. heavy cream
• 1/2 c. sour cream
• 1 c. freshly shredded Cheddar cheese, divided
• 3 green onions, sliced, divided