Shiitake Mushroom and Quinoa Soup

I ordered too many mushrooms from my online CSA this week. This recipe uses the caps for about 1/2 lb. of shiitake mushrooms. I threw the leftover peelings, extra celery, mushroom stems, etc., in a slow cooker to make vegetable broth with the trimmings, so there was very little waste.

1 tablespoon oil

2 tablespoons dried minced onion

2 celery stalks, finely chopped

3 cloves minced garlic

21/2 cups sliced shiitake mushroom caps

1/2 cup dry quinoa (pre-rinsed if needed)

1 teaspoon dry crushed rosemary

4 cups low-sodium vegetable stock (I make my own)

2 cups sweet potato, peeled and sliced into 1/2 inch cubes
1/2 cup turnip, peeled and sliced into 1/2 inch cubes (optional)

1/2 teaspoon dried lemon peel

2 tablespoons lemon juice

ground pepper to taste

Heat the oil over medium heat in a Dutch oven. Add the celery and garlic and cook until the celery becomes tender. Add the minced onion and mushrooms and cook until the mushrooms are tender, about 5 minutes. Add a little broth if the mixture becomes too dry. Stir in the other ingredients except the lemon juice and pepper, then increase the heat to high. Bring to a boil, then reduce heat and cook about 12-15 minutes until the quinoa is done and the sweet potatoes are tender. Remove from heat, stir in the lemon juice, season to taste with the pepper.