Rinse,peel, and cube potatoes and place in slow cooker.
Chop onion and place in slow cooker.
Add pureed pumpkin, garlic, vegetable broth, water, plant milk, oat flour, rosemary, salt, and pepper to slow cooker.
Stir to combine ingredients.
Slow cook on low for 6 hours (high for 4 hours) or until the potato is cooked. Stir occasionally so that the bottom doesn't burn.
Once done, the soup can either be pureed with an immersion blender or left chunky.
This soup will keep in the refrigerator for 3-4 days. It can also be frozen for up to a month.
*Make sure to get regular pureed pumpkin, not pumpkin pie pumpkin.