1. Pre-soak the beans in 4 cups water overnight. Drain beans.
2. In a large pot, bring the beans up to a simmer in 4 cups of fresh, salted water (1 tablespoon). Cook until tender, let cool in liquid and reserve 1/2 cup cooking liquid.
3. In a sauté pan, render sausage in 1 tablespoon of oil, add onions, carrots, celery, and garlic, and cook until tender. Add beans and the 1/2 cup cooking liquid until emulsified. Add butter and take off heat. When butter is melted, add arugula.
4. Meanwhile, salt and pepper shrimp. Drizzle with olive oil and grill on high heat about 2 minutes per side. Place bean and sausage mixture in bowl and top with grilled shrimp.