North Carolina Peanut Soup

1/4 cup chopped onion
1/4 cup chopped celery
1 teaspoon crushed garlic
3 tablespoon unsalted butter
2 teaspoon curry powder
2 tablespoon flour
2 (13 3/4 ounce) cans chicken broth
1/4 teaspoon pepper
1 cup peanut butter
1/2 cup plain yogurt
2 tablespoon lemon juice
1/2 cup chopped peanuts
1/4 cup chopped parsley

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