1

Combine porcini mushrooms and water in 1-cup glass measure. Let stand until mushrooms are softened, about 20 minutes. Transfer mushrooms with their liquid to sieve set over medium bowl. Reserve liquid. Rinse mushrooms to remove any grit, then pat dry and finely chop. Pour reserved mushroom liquid into 3- or 4-quart slow cooker.

2

Heat oil in large nonstick skillet over medium heat. Add onion and cook, stirring, until softened, about 5 minutes. Add carrot and celery and cook, stirring, until slightly softened, about 4 minutes. Add garlic and cook, stirring constantly, until fragrant, about 30 seconds longer.

3

Combine porcini mushrooms, cremini mushrooms, onion mixture, salt, pepper, and broth in slow cooker. Cover and cook 3 hours on High or 6 hours on Low.

4

Combine porcini mushrooms, cremini mushrooms, onion mixture, salt, pepper, and broth in slow cooker. Cover and cook about 5 minutes on each side. Transfer to paper towel-lined plate to drain. When cool, break into 1-inch pieces. Set aside.

5

Ladle soup evenly into 4 bowls. Top each serving with 2 tablespoons Parmesan and one-fourth of prosciutto; sprinkle with parsley.

6

Per serving: about 1 cup soup and 2 tablespoons cheese