COOK IT.
Fire up your Nexgrill to medium-high heat.
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.
Place chicken thighs on direct heat and close the lid.
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.
Transfer thighs to a platter, and let them rest for 5 minutes.
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.
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.
Spread the reserved dressing across the cut sides of your toasted brioche buns.
Assemble the sandwiches with buns, chicken, and fennel salad.