1 tablespoon butter
1 medium onion, chopped
1 cup chopped celery
9 cups water
1 package (16 ounces) dried green split peas
2 cups cubed peeled sweet potatoes or russet potatoes
1 bay leaf
1-1/2 teaspoons sea salt
1 teaspoon dried thyme
1/2 teaspoon pepper
Melt the butter in a large saucepan. Add the onion and celery and cook until tender. Stir in the water, peas, potatoes, bay leaf, salt, thyme and pepper. Bring to a boil.
Reduce heat; cover and simmer for 70-80 minutes or until peas are tender.Remove from heat. Discard bay leaf. Using an immersing (stick) blender, puree the soup until completely smooth.
Or cool slightly and puree in a blender in batches until smooth. Serve garnished with sour cream, yogurt, cheddar cheese, croutons, or nutmeg.