Combine broth and cornstarch in a small saucepan, stirring with a whisk. Bring broth mixture to a boil over medium heat; cook 1 minute, stirring constantly. Remove from heat, and stir in the remaining ingredients. Cover and chill. Stir before using.
Note: Store remaining vinaigrette in refrigerator for up to a week.
Dijon Vinaigrette: Add 2 teaspoons Dijon mustard to broth mixture with red wine vinegar and remaining ingredients.
Roasted Garlic Vinaigrette: Add 2 teaspoons bottled minced roasted garlic to broth mixture with red wine vinegar and remaining ingredients.
Cumin-Lime Vinaigrette: Omit vinegar. Add 3 tablespoons fresh lime juice and 1/4 teaspoon ground cumin to broth mixture with oil and remaining ingredients.