Remove the skin from the sweet potato and slice it length-wise.
Peel the onion and avocado and slice them as well.
Brush or spray the sweet potato slices, avocado slices, and onion well with olive oil or the oil of your choice.
Sprinkle the slices with salt, pepper, and za'atar (if using it).
Place the sweet potato slices on a heated grill and grill for 6–8 minutes on each side. Add the onion slices when the sweet potatoes are being flipped and grill for 3–4 minutes on each slide. At this point, you can also grill the avocado slices for about 2–3 minutes on each side.
Once the veggies are grilled, cut them into bite-sized pieces.
Chop up the celery, jalapeño, and parsley as well.
Drain and rinse the chickpeas.
Place the mixed greens in a bowl and add in the celery, jalapeño, grilled sweet potato, grilled avocado, grilled onions, parsley, drained and rinsed chickpeas, and walnuts.
Enjoy as is, or drizzle with some blueberry balsamic or dressing of your choice and enjoy!