2 - Tablespoon unsalted butter or margarine
3 - large red onions, thinly sliced
1 - cup pearl onions, blanched and peeled
1/2 - teaspoon salt
1/2 - teaspoon black pepper
2-1/2 - pounds boneless pork loin, tied
1/2 - cup sherry
2 - Tablespoons Italian parsley, chopped
1-1/2 - Tablespoons cornstarch
2 - Tablespoons water

• In a medium skillet over medium heat, add the butter and melt. 
• Next, add the red onions and pearl onions. 
• Sauté until vegetables are soft. 
• You want to season with salt and pepper.
  
• Rub the pork loin with salt and pepper and place in the slow cooker. 
• Add the sautéed onions, sherry and parsley.
  
• Cover and cook on LOW for 8 to 10 hours or on HIGH for 5 to 6 hours.
  
• Remove the pork loin from the slow cooker and let stand for 15 minutes before slicing.
  
• Combine the cornstarch and water and add to the juice in the slow cooker to thicken the sauce. 
• Serve the pork loin with the onions and sherry sauce.