Place potatoes, carrot and garlic in a Dutch oven and cover with water. Bring to a boil. Reduce heat; cover and simmer for 15-20 minutes or until tender. Drain. Place 3 cups potato mixture in a bowl and mash. Set aside mashed potatoes and remaining potato
In a skillet, cook sausage and onion over medium heat until meat is no longer pink; drain and set aside. In a soup kettle, melt butter. Stir in flour until smooth; gradually add the milk. Bring to a boil; cook and stir for 2 minutes or until soup is thickened.
Add the parsley, salt, bouillon, seasoned salt and pepper; mix well. add the mashed potato mixture; cook and stir until heated through. Add the reserved potato and sausage mixtures. Heat through.