Place potato halves and garlic clove in a large saucepan; cover with water. Bring to a boil; reduce heat, and simmer 20 minutes or until tender. Drain. Return potato halves and garlic clove to pan. Add blue cheese and next 4 ingredients (through black pepper); mash with a potato masher to desired consistency. Cool slightly. Shape the potato mixture into 12 (1/2-inch-thick) cakes; set aside.
Place walnuts and bread in a food processor; pulse 10 times or until coarse crumbs form. Place in a shallow bowl or pie plate. Dredge potato cakes in breadcrumb mixture.
Heat 1 1/2 teaspoons olive oil in a large nonstick skillet over medium heat. Add 6 potato cakes, and cook 2 minutes on each side or until browned. Remove cakes from pan; cover and keep warm. Repeat procedure with the remaining 1 1/2 teaspoons olive oil and 6 potato cakes.