Combine all ingredients for the dressing and mix well. Refrigerate until ready to use.
In a medium non-stick skillet, heat 1 tbsp of olive oil over medium heat. Add the onion and diced bell peppers, seasoning with some salt, pepper, and the ground cumin. Allow to saute until the onions turn translucent and the peppers soften.
While the peppers and onions are cooking, season both sides of the chicken with the lemon pepper and some salt. If desired, you can place each chicken breast between two sheets of plastic wrap and pound thinner before you season it. Once the chicken is seasoned, brown it on both sides in a non-stick skillet in a little olive oil and butter (optional) until the chicken is cooked through. Depending on the thickness of the chicken, this will take about 4 minutes per side.
Build your salads. Place your preffered lettuce on a plate or in a bowl, and top with diced avocado, tomatoes, shredded cheese, and any other topping you desire. Place the sauteed peppers and onions on top, then the cooked, sliced chicken, and top with the dressing.