Place chicken breasts in a reusable silicone bag or glass container. In a small bowl, whisk together olive oil, lemon juice, soy sauce, worcestershire sauce, garlic, kosher salt, pepper, and lemon zest. Pour marinade over the chicken and toss to coat. Cover and refrigerate for 30 minutes (or overnight).

In a small bowl, combine the Pesto Aioli ingredients. Cover and place in the refrigerator until ready. Prep the quick pickled onions and set aside until ready to use.

Heat grill to medium-high heat (approximately 450 degrees F). Place chicken on direct heat and cook for 3-5 minutes per side. Move chicken away from direct heat and cook for an additional 3-5 minutes or until the internal temperature of the thickest part of the chicken reads 157 degrees F.

Add cheese slices and close grill to allow cheese to melt. Remove from grill when the internal temperature reaches 160 degrees F and let rest for at least 5 minutes.

(Optional) Toast the focaccia buns cut side down for a minute or two. Place the bottom bun on a plate followed by some arugula, a healthy amount of Pesto Aioli, grilled chicken, avocado slices, pickled onions, and then add more Pesto Aioli to the cut-side of the top bun and place on top. Cut in half and enjoy!