How to Make It
Heat oil in a large nonstick skillet over medium. Add onion, carrots, parsnips, and garlic; cover and cook until barely tender, about 5 minutes. Place mixture in a 5-quart slow cooker. Add sausage, beans, tomatoes, broth, thyme, salt, pepper, and bay leaf. Cover and cook on LOW untilvegetables are tender, about 8 hours.
Meanwhile, melt butter in a small skillet over medium. Add panko, and cook, stirring often, until lightly browned, about 3 minutes. Set aside to cool.
Combine panko mixture, cheese, and parsley in a small bowl. Remove and discard bay leaf; top stew with panko mixture before serving.