Place dry beans in a bowl and cover with water. Soak overnight, then drain and rinse.
Place soaked peas in the slow cooker. Add sausage, onion, garlic, salt, and pepper. Pour broth over the peas, and then enough water to cover the contents (about two cups). Stir everything together, cover, and cook on low for 8-10 hours.
A half hour before serving, stir in instant rice and turn heat to warm (if possible on your slow cooker). Add salt and pepper to taste, then serve.