Place pepper over the flame of a gas burner on medium heat. Turn frequently until the skin is thoroughly charred on all sides. If you dont have a gas burner, roast pepper under the broiler.
Remove charred pepper to a bowl and cover with plastic wrap. Allow to cool enough to handle. Wipe off charred skin, stem and seed the pepper, then thinly slice. Reserve.
For the guacamole, cut the avocado in half and remove the pit. Scoop out the flesh and transfer to a bowl with the lime juice and 1/4 of the minced yellow onion. Lightly smash the avocado with a fork or masher to combine. Season with salt and pepper, to taste. Cover with a piece of plastic wrap, pressing it down directly on top of the guacamole and reserve.
Place a medium to large skillet over medium-high heat. Add oil and heat until it ripples. Add remaining minced onion and cook, stirring frequently until light brown, about 4 minutes. Add garlic and chicken, season with a little salt and pepper, and cook until the chicken is cooked through, about 4-5 minutes. Remove skillet from heat and add the parsley and basil, toss to combine.
While the chicken is cooking, in a small bowl, whisk together honey, balsamic and soy sauce. Reserve dressing.
To serve, arrange lettuce leaves on a platter or individual plates. Fill each lettuce cup with a scoop of guacamole and some of the chicken mixture. Top each filled cup with roasted red peppers and drizzle with dressing.