Asparagus, Morel and Walleye Soup with Rye Croutons

Preheat oven to 350°. Spread bread cubes on a baking sheet. Bake until crisp, about 15 minutes. Meanwhile, melt 3 tablespoons butter. Place in a large bowl; stir in 2 tablespoons white miso and 1 clove minced garlic. Add bread cubes; toss to coat. Return croutons to baking sheet. Bake until crisp and golden, 3 to 5 minutes more.

In a 6-quart Dutch oven, combine the water and dried morels. Bring to a boil. Using a slotted spoon, remove morels from the water, coarsely chop and set aside. (If you'd like to garnish the soup with chopped asparagus, take this moment to briefly blanch a handful of tips, remove with a slotted spoon, shock with cold water and set aside.) Transfer cooking water to a bowl and set aside.

In the Dutch oven, melt 3 tablespoons butter over medium. Add leeks and 3 cloves minced garlic. Cook until leeks are tender, 5 to 8 minutes. Add morel cooking water, the asparagus, 2 tablespoons white miso, the mirin, tamari, salt and pepper to Dutch oven. Bring to a boil; reduce heat. Simmer, uncovered, 10 minutes.

Using an immersion blender, puree soup until smooth. (Or transfer to a regular blender in batches. Cover, blend until smooth and return to Dutch oven.) Return to a simmer.

In a small bowl, whisk together sour cream and about 1/2 cup of the hot soup. Whisk mixture into the soup.

Add fish and morels to Dutch oven. (If you like, reserve a few morels to garnish the soup.) Cook until fish is opaque, 4 to 6 minutes. Serve soup topped with additional sour cream, chives, dill and the croutons (and, if you like, the reserved asparagus and morels).