½ cup unsalted butter
2 cups finely chopped sweet onions (such as Vidalia®)
1 cup celery root (celeriac)
peeled and finely chopped
2 ½ tablespoons chopped green bell pepper
3 tablespoons chopped red bell pepper
2 ½ tablespoons chopped yellow bell pepper
1 pound peeled crawfish tails
2 teaspoons minced garlic
3 bay leaves
1 ½ tablespoons all-purpose flour
½ cup low-sodium chicken broth
½ cup water
1 teaspoon coarse smoked salt flakes
1 pinch cayenne pepper
or to taste
3 tablespoons finely chopped fresh parsley
3 tablespoons green onions
chopped