In large pot, combine potatoes with enough cold water to cover by 1 inch. Add 1 teaspoon salt. Simmer 30 minutes or until fork-tender.
In skillet, heat 2 tablespoons oil. Add leek, shallots, and garlic; saute 3 minutes to slightly soften. Place in large bowl.
Drain potatoes. Slice and add leeks; toss to combine.
Toss with 1/2 cup Italian dressing and cover to keep warm.
Grill Italian sausage and serve with warm salad. Makes 6 servings.