• Preparation
    20 Minutes
  • Cook Time
    12 Minutes
  • Serves
  • Difficulty

Behind the Recipe

Best. Chicken. Sandwich. Ever.

If you’re looking for the perfect summer sandwich without breaking a summer sweat, this is the recipe for you. There’s something about the mustardy homemade caesar spread, fresh and crisp fennel-basil slaw, and the char of grilled chicken thighs that is simply incredible together. 

Even if you’re new to fennel, you’ll find the fennel in this grilled chicken sandwich recipe has a wonderful way of balancing out the acidity and tang of the caesar dressing. It’s so much flavor without too much complexity. Plus, many of the ingredients (outside of fennel and cornichons) can probably be found in the back of your pantry or refrigerator. 

RECIPE TIPS: Just a few notes on how to marinade chicken thighs. 

  • Unlike beef, which can sit and soak in marinades for long periods of time (6 to 24 hours), chicken thighs aren’t as tough, and do better with a shorter marinade (30 minutes to 4 hours max). 
  • When chicken spends too much time marinating, it can actually make the chicken tougher. The acid within the marinade will begin to affect the protein strands within the meat, and mess with its texture. 
  • Chicken thighs are a little fattier than chicken breasts. Which means they will hold their moisture a little better, even if they’re left on the grill for a little while longer.  This makes chicken thighs a great pairing with bold, assertive marinades and sauces



  • 4 skinless, boneless chicken thighs (about 1.5 lbs. total)
  • 4 brioche buns
  • 1 medium fennel bulb, sliced thin + fronds coarsely chopped 
  • 1 c basil leaves, torn if large
  • 1 Tbsp. Dijon mustard
  • 2 tsp Worcestershire sauce
  • 2 garlic cloves, finely grated
  • 2 Tbsp fresh lemon juice (for marinade)
  • 2 tsp fresh lemon juice (for fennel salad) 
  • 2 tsp. freshly ground black pepper, plus more to taste
  • ⅓ c extra-virgin olive oil (for marinade)
  • 2 tsp. extra-virgin olive oil (for fennel salad)
  • 6 Tbsp. mayonnaise
  • ¼ c chopped cornichons (roughly 9 total) 
  • Kosher salt
  • Olive oil (for oiling grill grates)


  1. In a medium bowl, whisk together 1 tablespoon Dijon mustard, 2 teaspoons Worcestershire sauce, grated garlic, 2 tablespoons lemon juice, and 2 teaspoons of black pepper until well blended. 
  2. Slowly add in ⅓ cup extra-virgin olive oil, whisking constantly until the marinade is emulsified. 
  3. Transfer half of your mixture into a small bowl, and set aside. (You’ll use this in a moment to make the dressing). 
  4. Next, season the chicken thighs all over with salt, and place them in a bowl with one half of the marinade mixture. Turn the thighs to coat them well. Then, let them sit at room temperature for 30 minutes (or cover the bowl and chill it in the fridge for up to 4 hours) to soak up the mustard-y marinade.
  5. With the remaining ½ of the mixture, you’re going to make a dressing. Whisk in the mayonnaise and cornichons until well-blended. Add a pinch of salt to taste, and set aside.
  6. Slice brioche buns in half.

Cooking Instructions

  1. 1

    Fire up your Nexgrill to medium-high heat.

  2. 2

    Pro Tip: Lightly oil the grates before you place the chicken thighs on the grill. This will keep the chicken thighs from sticking when it’s time to turn them over.

  3. 3

    Place chicken thighs on direct heat and close the lid.

  4. 4

    Cook for 4-5 minutes, flip the chicken thighs, and let them cook an additional 4-5 minutes until deeply browned and cooked through. You’ll know they’re done when a digital thermometer inserted at the thickest part reads 165º.

  5. 5

    Transfer thighs to a platter, and let them rest for 5 minutes.

  6. 6

    While the thighs are resting, place brioche buns on the grill (cut side down) until lightly toasted, about 30 seconds. Transfer to the platter with chicken.

  7. 7

    In a medium bowl, toss together the sliced fennel, chopped fennel fronds, basil, 2 teaspoons of extra-virgin olive oil, and 2 teaspoons of lemon juice to combine. Then season with salt and pepper.

  8. 8

    Spread the reserved dressing across the cut sides of your toasted brioche buns.

  9. 9

    Assemble the sandwiches with buns, chicken, and fennel salad.

  10. 10

    Serve & enjoy!

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