Sweet Potatoes: Wrap potatoes in aluminum foil and set in a slow cooker. Cook on high heat for 1 hour.
Brussels Sprouts: Meanwhile, toss together cleaned Brussels sprouts, garlic, oil, salt, and pepper (if your sprouts are large, cut in half). Wrap in aluminum foil to create a pouch. Set aside.
Creamy Corn: Stir together all corn ingredients. Create an aluminum foil pouch, using a few layers to make it water-tight. Pour corn mixture into foil pouch and scrunch together to seal.
Cook: After 1 hour of cooking, flip sweet potatoes then set Brussels sprout and corn pouches on top of potatoes. Cover and continue cooking on high for 2 to 3 hours, or until sprouts and potatoes are tender. Optionally broil sprouts in the oven for a few minutes to crisp up the outsides.
Serve: Keep side dishes warm in the slow cooker until ready to serve. Serve sweet potatoes with a small spoonful of brown sugar, a slab of butter, and pecans. Grate parmesan over warm Brussels sprouts.