1lb fresh asparagus (trimmed and cut into 1-inch pieces)
1 Large Vidalia onion (diced)
1 carton vegetable broth
3 tablespoons salted butter
2 tablespoons flour
1 to 2 pinch salt
1.5 cups whole milk
1 cup sour cream
1/2 pint fresh blackberries (garnish)
1. Combine asparagus, chopped onion, and 1/2 of the vegetable broth in a Dutch oven. Cover and bring to a boil over high heat. Cook until asparagus is tender, about 12 minutes.
2. Process mixture in a blender until smooth, set aside.
3. Melt butter over medium-low heat in the same Dutch oven. Stir in flour and salt. Cook, stirring constantly, for 2 minutes.
4. Whisk in remaining vegetable broth, raise heat, and stir constantly until mixture boils. Stir in asparagus purée and milk.
5. Put two-thirds of the sour cream in a small bowl. Stir in a ladleful of hot soup, then add the mixture back into the Dutch oven.
6. Stir while heating the soup to serving temperature. Don't allow it to boil.
7. Garnish with a swirl of the remaining sour cream, some black raspberries and asparagus tips. Serve immediately