- ½ cup red wine vinegar
- 4 tsp. olive oil
- 2 Tbsp. country-style Dijon mustard
- 2 Tbsp. finely chopped tarragon
- 1 cup thinly sliced celery
- 8 oz. cooked chicken breast, boneless, skinless, cut into ½-inch cubes
- 1 cup red grapes
- 4 cups fresh spinach
- ¼ cup walnut halves
- Combine vinegar, oil, mustard, and tarragon in a small bowl; whisk to blend. Evenly divide dressing between 4 half-pint Mason jars. Set aside.
- Evenly layer celery, chicken, grapes, spinach, and walnuts on top of dressing in jars.
- Serve immediately or cover and refrigerate for up to 3 days. Shake before serving.