1. Combine the first five ingredients. Store in an airtight container in a cool dry place for up to 1 year. Yield: 4 batches (20 tablespoons total).
2. To prepare onion soup: In a saucepan, combine water and 5 tablespoons onion soup mix. Bring to a boil over medium-high heat, stirring occasionally. Reduce heat; simmer, uncovered, for 10 minutes, stirring occasionally. Yield: 3 servings.
3. To prepare roasted potatoes: In a bowl, toss potatoes and oil. Sprinkle with 5 tablespoons onion soup mix; toss to coat. Transfer to an ungreased 15-in. x 10-in. x 1-in. baking pan. Bake, uncovered, at 450° for 35-40 minutes or until tender, stirring occasionally. Yield: 6 servings.
4. To prepare onion dip: In a bowl, combine sour cream and 5 tablespoons onion soup mix; mix well. Refrigerate for at least 2 hours. Serve with vegetables, chips or crackers. Yield: 2 cups.