To prepare vinaigrette: In a screw-top jar, combine oil, vinegar, thyme, mustard and salt. Cover; shake well to mix.
To prepare salad: In a large bowl, toss together spinach, apple, onion, and dried cherries. Drizzle with 1/4 cup of the vinaigrette (reserve the rest for another use). Toss gently to coat. If desired, top individual servings with cheese.
Tips: To make ahead, prepare the vinaigrette as directed. Cover and chill for up to 1 week.
You can substitute 1/2 teaspoon dried thyme (crushed) for 2 teaspoons fresh.
1 vegetable, 1/2 fruit, 1 fat