Creamy Potato Leek Soup

Name: Creamy Potato Leek Soup
Prep time: 15 min
Cook time: 40 min
Total time: 55 min
Cuisine: American, French
Ingredients: 1/4 cup unsalted butter; 4 large leeks; 4 cloves garlic (diced); 2 pounds Yukon gold potatoes (about 5 medium potatoes); 4 cups vegetable stock; 2 sprigs fresh thyme; 1 sprig fresh sage; 2 bay leaves; 1 teaspoon kosher salt; 1/2 teaspoon black pepper; 1/2 teaspoon cayenne pepper (optional); 1 cup heavy cream (substitute whole milk); 2 tablespoons fresh chives (for garnish); 5 cups sourdough bread (about 1 medium loaf); 1/2 cup unsalted butter (substitute olive oil); 2 tablespoons parmesan cheese; 1 teaspoon garlic powder; 1/2 teaspoon kosher salt; 1/4 teaspoon black pepper