Preheat oven to 425°F. Arrange butternut squash, onion, carrots, leeks, tomatoes, and garlic on a baking sheet. Coat with olive oil, sprinkle with salt and pepper, and distribute thyme sprigs. Roast for 45 minutes to 1 hour, until squash is fork-tender and all vegetables are roasted. Remove any vegetables early if they are at risk of burning.
Transfer roasted vegetables to a blender or pot with 4 cups vegetable stock. Blend until smooth. Heat the soup over medium, stirring, and bring to a light simmer. Add ginger powder, turmeric, and chili powder. Stir in heavy cream and adjust salt to taste.
For grilled cheese, layer sharp cheddar and a slice of American cheese between sourdough bread slices. Melt butter in a skillet over medium heat. Toast one side with a lid on, then flip with a fresh pad of butter to toast the other side. Remove when golden and cheese is melted. For a cheese pull, let the sandwich sit for 30 seconds after slicing to separate.
Serve soup with a drizzle of heavy cream, olive oil, and chili oil. Pair with the grilled cheese for dipping.
