Ingredients

• 6 long parsley sprigs, divided
• 1 3/4 cups reduced-sodium chicken broth
• 1 large garlic clove, minced
• 2 teaspoon unflavored gelatin (from 1 envelope)
• 3 tablespoons water
• 1 (3/4-pound) piece baked ham, cut into 1/2-inch cubes (2 cups)
• 1/2 cup mayonnaise
• 2 tablespoons Dijon mustard
• 2 tablespoons white-wine vinegar
• 2 celery ribs, finely chopped (1 cup)
• 1/4 cup chopped cornichons or sour gherkins
• 1 pound boiled potatoes, peeled and cut into 1/2-inch cubes (2 1/2 cups)
• 1 (10-ounce) box frozen baby peas, thawed
• 2 teaspoons finely chopped marjoram
• 3 tablespoons extra-virgin olive oil
• Equipment: 4 (16-ounce) wide jars or containers with lids
• Garnish: celery leaves

Instructions

1. Chop enough parsley leaves to measure 1 tablespoon; reserve. Chop remaining leaves and stems and simmer with broth and garlic in a small saucepan, covered, 5 minutes.
2. Meanwhile, sprinkle gelatin over water in a medium bowl and let soften 1 minute. Strain broth through a fine-mesh sieve into bowl with gelatin and stir to dissolve. Season with salt and pepper. Set bowl in an ice bath and cool to room temperature, stirring.
3. Toss ham with reserved parsley and divide among jars. Pour gelatin on top and chill until set, at least 1 hour.
4. Make potato salad: Whisk together mayonnaise, mustard, vinegar, 1/4 teaspoon salt, and 1/4 teaspoon pepper in a large bowl. Stir in celery, cornichons, and potatoes.
5. Whisk together mayonnaise, mustard, vinegar, 1/4 teaspoon salt, and 1/4 teaspoon pepper in a large bowl. Stir in celery, cornichons, and potatoes.
6. Mash peas: Pulse peas with marjoram, oil, 1/2 teaspoon pepper, and 1/4 teaspoon salt in a food processor to a coarse mash.
7. Pulse peas with marjoram, oil, 1/2 teaspoon pepper, and 1/4 teaspoon salt in a food processor to a coarse mash.
8. Assemble jars: Layer peas, then potato salad, over ham.
9. Layer peas, then potato salad, over ham.