Pumpkin Apple Soup with Salsify Garnish

Name: Pumpkin Apple Soup with Salsify Garnish
Ingredients: 1 medium pumpkin (any variety will do, but my favorites are Kabocha, Galeux d'Eysines & Red Kuri); 2 cups vegetable stock; 1/2 cup whole milk (or coconut milk for a richer soup); 1/4 cup heavy cream; 2 carrots, chopped; 1 serrano pepper, chopped; 8 sage leaves; 1 cup applesauce; 3 tablespoons agave nectar; 1 teaspoon kosher salt; 2 teaspoons ginger root, minced; 2 teaspoons nutmeg; 1 teaspoon allspice; 2 salsify roots, peeled and shaved; 3 tablespoons butter, divided