In a blender, combine the oil, vinegar, parsley, salt, sugar, anchovy fillets and garlic. Puree until smooth.
Bring a large pot of salted water to a boil. Add potatoes and cook until tender but still firm, about 15 minutes. Drain, cool and cut into cubes. Pour prepared vinaigrette over potatoes and marinate overnight.
Place sausage in a large, deep skillet. Cook over medium high heat until evenly brown. Drain, crumble and set aside.
Combine the potatoes and dressing, sausage, green onions, parsley and olives. Toss together well and season with salt and pepper to taste.
