Preheat your oven to 425 degrees.
Take 1-1/2 pounds of trimmed asparagus and place them on a high-sided sheet pan. Drizzle with 2 tablespoons of olive oil and season generously with Kosher salt and black pepper for flavor.
Roast the asparagus in the oven for about 12 minutes.
Transfer the asparagus to a high-powered blender and pour in 1-1/2 cups of vegetable stock. Start blending on the lowest speed, gradually increasing to the highest speed. Blend until the mixture is smooth and hot, taking about 6 minutes.
Lower the blender speed and add in 1/2 cup of heavy cream. Blend for an additional 30 seconds just to incorporate the dairy.
Taste your soup and adjust the seasoning with more salt and pepper if needed.
Serve the soup warm, garnished with a dollop of sour cream and a sprinkle of minced fresh dill.