Preheat oven to 375 degrees F (190 degrees C). Line a 15x10-inch baking pan with foil or parchment paper.
To roast fresh pumpkin for the soup, halve the pumpkin; remove seeds and strings. Place cut sides down on prepared pan. Bake 1 hour or until tender; remove. Turn over and let cool.
Scoop out pulp and discard skin. Working in batches, place pumpkin in a blender or food processor and blend or process until smooth.
Transfer to a fine-mesh sieve lined with a double thickness of 100% cotton cheesecloth. Let stand 1 hour, then press lightly to remove liquid. Discard liquid. You should have 1 3/4 cups.
In a 4 to 5-quart pot, heat Olive Oil (1 tablespoon) over medium-high. Add the Onion (1 1/2 cup) and Garlic (4 clove). Cook and stir for about 4 minutes or until tender.
Add the Chicken Broth (3 cup), Water (1 cup), and Potato (1). Bring to a boil and reduce heat. Cover and simmer for 15 minutes or until potato is tender.
Stir in the 100% Pumpkin Purée (1 can) or the fresh roast pumpkin. Using an immersion blender, blend until smooth. (Or working in batches, process in a blender.) Simmer over low heat.
Slowly add the Gruyère Cheese (1 cup) until melted.
Stir in the Heavy Cream (1/4 cup) along with the Salt and Pepper (to taste). Heat through.
While the soup is simmering, spread the Rustic Bread (8 ounce) in the prepared pan. Toss with the remaining Olive Oil (2 tablespoon) to coat. Sprinkle with the Manchego Cheese (1/4 cup). Bake about 15 minutes or until golden brown, stirring once.
When serving, top each bowl of soup with croutons. Enjoy!