Boil potatoes in salted water. Drain and mash.
In a large saucepan, melt butter. Add bell pepper, onion, celery, and garlic. Cook, stirring occasionally, until very soft. Add shrimp and cook until shrimp are pink, stirring often. Remove from heat.
In a large bowl, thoroughly combine mashed potatoes, shrimp mixture, rice, parsley, eggs, flour, and Cajun seasoning. Refrigerate at least 1 hour.
Add about ¼-inch oil to large skillet and heat over medium-high heat.
Form shrimp mixture into a boulette or patty if you prefer. (You may need to add more flour if boulettes won’t stay together.)
Fry until golden brown.
Goes great with white beans and rice!