Mustard Seed Chicken Salad with Pickled Onions

Name: Mustard Seed Chicken Salad with Pickled Onions
Prep time: 25 min
Cook time: 5 min
Total time: 30 min
Yield: 4 servings
Cuisine: American
Ingredients: 1 medium (200 g) red onion, thinly sliced; ½ cup (120 ml) red wine vinegar; ½ cup (120 ml) water; 2 tablespoons (25 g) granulated sugar; ¾ teaspoon (4 g) kosher salt; ½ teaspoon (2 g) yellow mustard seeds; 3 whole black peppercorns; 1 pound (450 g) cooked rotisserie chicken, skin and bones removed, meat shredded or torn into bite-size pieces; ½ cup (120 ml) mayonnaise; 2 tablespoons (18 g) yellow mustard seeds, toasted, lightly toasted, still whole; 2 medium stalks (100 g) celery stalks, finely diced; 1 tablespoon (3 g) fresh tarragon, finely chopped, or 1 teaspoon dried; 1 tablespoon (3 g) fresh dill, finely chopped; 1 tablespoon (15 ml) fresh lemon juice; to taste kosher salt; to taste freshly ground black pepper

From the MyKitchenBank Kitchen

A tangy, bright chicken salad built on mustard seed crunch and homemade pickled onions. Shredded rotisserie chicken is tossed with creamy mayonnaise, whole mustard seeds for texture, tart pickled red onions, crisp celery, and fresh herbs. The result is complex and satisfying—perfect on toasted bread, crackers, or greens. Make the pickled onions ahead for best flavor.

Prep: 25 min
Cook: 5 min
Wait: 30 min
Total: 1 hr
Makes: About 2½ cups (enough for 4 sandwiches or 2 large salads)

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Ingredients

4 servings

For the pickled onions
1 medium (200 g) red onion, thinly sliced
½ cup (120 ml) red wine vinegar
½ cup (120 ml) water
2 tablespoons (25 g) granulated sugar
¾ teaspoon (4 g) kosher salt
½ teaspoon (2 g) yellow mustard seeds
3 whole black peppercorns
For the salad
1 pound (450 g) cooked rotisserie chicken, skin and bones removed, meat shredded or torn into bite-size pieces
½ cup (120 ml) mayonnaise
2 tablespoons (18 g) yellow mustard seeds, toasted, lightly toasted, still whole
2 medium stalks (100 g) celery stalks, finely diced
1 tablespoon (3 g) fresh tarragon, finely chopped, or 1 teaspoon dried
1 tablespoon (3 g) fresh dill, finely chopped
1 tablespoon (15 ml) fresh lemon juice
to taste kosher salt
to taste freshly ground black pepper

Equipment (5)

Small saucepan
Small glass jar or container
Large bowl
Cutting board and knife
Wooden spoon or spatula

Steps

Before you start

Pickled onions benefit from 2–4 hours (or up to overnight) chilling before assembly, so make them first or ahead
Have all ingredients measured and prepped before assembling the salad
Use a rotisserie chicken at room temperature, or warm it briefly so it shreds cleanly

1
Make the pickling brine
- In a small saucepan, combine 0.5 cup (120 ml) red wine vinegar, 0.5 cup (120 ml) water, 2 tablespoons (25 g) sugar, and 0.75 teaspoon (4 g) kosher salt.
- Bring to a simmer over medium heat, stirring until the sugar and salt dissolve, about 2 minutes.
- Add 0.5 teaspoon (2 g) yellow mustard seeds and 3 whole black peppercorns.
- Remove from heat and let cool for 2 minutes.
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Ready when: Sugar and salt dissolve, liquid is steaming and aromatic
Tip: Don't let the brine boil vigorously; you want a gentle simmer to preserve the delicate mustard seed flavor.
2
Pickle the onions
- Place the sliced red onion into a small glass jar or container.
- Pour the warm brine over the onions, making sure they're submerged.
- Let cool to room temperature, then cover and refrigerate for at least 2 hours, or up to overnight.
- The flavor deepens as they sit.
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Ready when: Onions are deep pink or red, tender but still crisp, brine is cool
Tip: Make these ahead—pickled onions taste better after a few hours and will keep up to 2 weeks in the fridge.
3
Toast the mustard seeds
- In a small dry skillet over medium heat, toast 2 tablespoons (18 g) yellow mustard seeds, shaking the pan frequently, for 2–3 minutes until fragrant and lightly browned.
- Transfer immediately to a plate to cool.
- Don't skip this step—toasting brings out nutty depth.
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Ready when: Seeds are light brown and smell warm and spicy; they pop slightly when you shake the pan
Tip: Watch the seeds carefully—they burn quickly. If they start smoking or turn dark brown, discard and start over.
4
Prepare the chickenOven 300°F / 150°C
- If using a warm rotisserie chicken, pull the meat from the bones and skin, discarding any cartilage or gristle.
- Tear or shred the chicken into bite-size pieces (about 1–1.5 inches / 2.5–4 cm).
- You should have about 1 pound (450 g) of meat.
- If the chicken is cold, you can warm it gently in a 300°F (150°C) oven for 5 minutes to make it easier to shred.
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Ready when: Chicken is in uniform bite-size pieces, no skin or bones remain
Tip: Don't shred the chicken too finely—you want some texture. Larger pieces stay juicier in the final salad.
5
Dice the celery
- Rinse 2 medium celery stalks and pat dry.
- Trim the ends and remove any tough outer strings by slicing lengthwise and peeling them away.
- Dice the celery into small pieces about 0.25 inch (6 mm) in size.
- You should have about 1 cup (100 g) of diced celery.
- Place in a large bowl.
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Ready when: Celery is finely and evenly diced, ready to toss
Tip: Keep the celery crisp by adding it to the bowl just before mixing to avoid it absorbing moisture from the mayo.
6
Assemble the salad
- To the bowl with celery, add the shredded chicken, 0.5 cup (120 ml) mayonnaise, the cooled toasted mustard seeds, 1 tablespoon (3 g) chopped fresh tarragon, 1 tablespoon (3 g) chopped fresh dill, and 1 tablespoon (15 ml) fresh lemon juice.
- Gently toss everything together until the chicken is evenly coated with mayo and the seeds and herbs are distributed throughout.
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Ready when: All ingredients are well combined, creamy, and no dry bits of chicken remain
Tip: Fold gently rather than stirring vigorously—you want to keep the chicken pieces whole and the texture light.
7
Add the pickled onions and season
- Drain the pickled onions well (reserve the brine for a salad dressing or to cover any extra onions for storage).
- Fold 0.5 cup (about 70 g) of the pickled onions into the salad, along with any whole mustard seeds and peppercorns that cling to them.
- Taste the salad and add kosher salt and freshly ground black pepper to taste—go easy on the salt at first, as the pickled onions already contribute tang.
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Ready when: Pink onion pieces are evenly distributed, salad is creamy and flecked with mustard seeds and herbs
Tip: Reserve any extra pickled onions to use on sandwiches, salads, or burgers later—they keep up to 2 weeks.
8
Chill and serve
- Cover and refrigerate the salad for at least 15 minutes before serving (or up to 1 day).
- This allows the flavors to meld and the salad to firm up slightly.
- Serve on toasted bread, crackers, lettuce cups, or as a bed for greens.
- For a sandwich, use about 0.75 cup (180 ml) of salad per sandwich.
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Ready when: Salad is cold, creamy, and the flavors have melded together
Tip: If making ahead, wait to add the pickled onions until just before serving (or a few hours ahead max) so they don't make the salad watery.

Good to know

Tips

Toast the mustard seeds dry in a skillet before using—this brings out their warm, nutty flavor and is essential to the salad's character.
Make the pickled onions ahead and let them chill for at least 2 hours, preferably overnight, so the flavors are bright and the onions are tender but still crisp.
Keep the salad components separate until the last moment if you're serving throughout the day—fold in the pickled onions shortly before eating to prevent the salad from becoming watery.
For a lighter version, replace half the mayonnaise with Greek yogurt or crème fraîche; you'll get tanginess that complements the pickled onions without heaviness.

Make ahead

Pickled onions can be made up to 2 weeks ahead. The salad itself is best assembled no more than 1 day ahead, and tastes freshest within 6–8 hours of mixing.

Storage & reheating

Room temperature: not recommended (mayonnaise should not sit out more than 2 hours). Refrigerator: cover and store for up to 1 day; flavors are brightest on the first day. Freezer: not suitable due to the mayonnaise base. Pickled onions keep in the refrigerator in their brine for up to 2 weeks.

Substitutions

fresh tarragon → fresh chives, fresh parsley, or 1 teaspoon of dry tarragon. Tarragon adds a subtle anise note; chives are milder and more onion-forward. Parsley adds freshness without as much flavor. Adjust to your taste.
fresh dill → fresh chervil, fresh parsley, or 1 teaspoon of dry dill. Dill complements the pickled onions beautifully. Parsley works as a neutral swap, though you'll lose the distinctive dill flavor.
red wine vinegar → white wine vinegar or apple cider vinegar. White wine vinegar is milder and slightly sharper; apple cider vinegar adds more sweetness. Both work, though red wine vinegar's richness is ideal here.
mayonnaise → Greek yogurt (use 0.25 cup / 60 ml mayo + 0.25 cup / 60 ml Greek yogurt) or Hellmann's/Best Foods mayo. Greek yogurt lightens the salad and adds tanginess, but reduces creaminess slightly. Use a neutral-flavored mayo brand, not flavored varieties.