Preheat oven to 375 °F. Cut 1/2 loaf rosemary sourdough into crouton sized pieces. Crisp in oven for about 10 minutes, until crunchy
Increase oven temperature to 400 °F. Cut the tops off of 2 pie pumpkins. Remove seeds and strings. Roast for 25 minutes until fork tender.
Heat 3 tbsp butter on medium heat in a soup pot. Add 1 yellow onion and cook for 5-6 minutes. Add 2 cloves garlic, stir until fragrant. About 30 seconds.
Add 3 c chicken broth, 1 c milk, 4 russet potatoes. Bring to a gentle boil and then reduce to a simmer. Cover and simmer for 10-15 minutes, until potatoes are fork tender.
Add 1 tsp salt, ½ tsp black pepper, ½ tsp thyme, ¼ tsp paprika, ⅛ tsp nutmeg. Stir.
Carefully scoop the centers of the pie pumpkins and add the pumpkin pulp to soup. Stir. Add 1 handful at a time of 1-2 c sharp cheddar cheese, stirring in between to make sure it melts evenly.
Optional: Blend soup if desired. I like it chunky.
Serve in pumpkins or bowls, add a handful of croutons to the top and sprinkle black pepper.
Optional: Top with bacon, crispy shallots, a drizzle of cream or melted butter.