To make the brine: Dissolve the salt in the warm water and allow the water to cool. Place the chicken in the brine for 15 to 30 minutes, or up to overnight. If brining the chicken longer than 30 minutes, place it in the refrigerator. After the chicken is finished brining, rinse and pat it dry. (If you have brined the chicken in the refrigerator, let it come to room temperature before baking.)
Preheat the oven to 450°F. Coat the chicken breast halves with the BBQ sauce. Set them on a rimmed baking sheet and bake for 15 to 18 minutes, until the sauce on the chicken starts to turn brown.
While the chicken is baking, prepare the rest of the salad ingredients: Arrange the lettuce on one large platter or 3 or 4 individual plates. Top the lettuce with rows of egg, bacon, avocado, and tomato.
When the chicken is finished, let it rest for 5 minutes before cutting.
While the chicken is resting, make the dressing by blending the mayo, jalapeño, and lime juice together in a blender or small food processor.
Cut the chicken into 1-inch cubes and plate its row alongside the others.
Sprinkle the salt, pepper, and onion, if desired, over the top. Drizzle the salad with the dressing and garnish with cilantro, if desired.
Enjoy warm or cold.
Tip
This amount of dressing will lightly dress the salad. If you prefer a more heavily dressed salad, the recipe is easily doubled.