Combine diced potatoes, chopped leeks, minced garlic, carrots, celery, dried thyme, rosemary, salt, and pepper in your slow cooker.
Pour in chicken or vegetable broth to cover the vegetables.
Cook on low for 6-8 hours or on high for 3-4 hours until the potatoes are tender.
Partially puree the chowder using an immersion blender or by transferring some to a blender, then return to the slow cooker for a thicker texture.
Stir in cream, sour cream, and shredded cheese until melted and well combined.
Finish with a sprinkle of fresh parsley and serve hot with your choice of toppings.

Variations & Tips
For a vegetarian version, ensure you use vegetable broth. You can also add other vegetables like corn or peas for additional texture and flavor. If you prefer a smokier taste, consider adding a few slices of cooked bacon or smoked paprika. For a dairy-free option, use coconut milk instead of cream and omit the cheese, or use a dairy-free cheese alternative. Adjust the herbs to your liking, perhaps adding a bay leaf during cooking for extra depth.