1. Place the ground sirloin in a large mixing bowl. Tear the bread slices into quarters or eighths, place in a food processor, and pulse until reduced to crumbs. Transfer to the bowl. Add the onion, garlic, parsley, salt, pepper, ¾ teaspoon of the paprika, the oregano, basil, and fennel. Using your hands or a large fork, mix gently but thoroughly, being careful not to compact the meat.

2. Make an aluminum-foil “cradle” that will help you easily remove the meatloaf from the slow cooker when it is done. Tear a sheet of foil that is about 20 inches long. Place the foil along the edge of the counter and tear in half the long way. Fold each piece in half lengthwise, then again in half lengthwise. Place the foil strips in the crock in a cross shape, centering them. The edges of the strips will hang over the edge of the crock. Place the meat mixture in the crock, on top of the strips. Shape the meat into an oval or round loaf, depending on the shape of your cooker, by pressing it gently, evening out the top and shaping it to fit your crock. Bend the foil strips in toward the meatloaf so they will not prevent the cover from closing properly.

3. In a small bowl, toss the potatoes with the melted butter and the remaining ¼ teaspoon paprika; arrange on top of the meatloaf. Cover and cook on LOW until an instant-read thermometer inserted into the center of the meatloaf reads 160° to 165°F, about 6 hours.

4. About 30 minutes before the end of cooking time, remove the cover, transfer the potatoes to a dish, and keep warm. Pour the ketchup over the meatloaf. Cover and cook another 30 minutes on LOW.

5. To serve, lift the meatloaf onto a serving platter, using the foil handles. Slide out and discard the foil strips, and arrange the potatoes around the meatloaf. Slice the meatloaf and serve hot.