Start by preparing the pita chips. Slice the pita into half and then into small triangles and toss together with the olive oil, za'atar and salt and pepper. Bake for about 10-12 minutes on the top rack until golden brown, flipping halfway through. Once ready, set aside.
Prep the salmon by adding the spices to a small bowl and seasoning each salmon fillet with the spice rub.
Heat a large skillet on medium heat, then coat the pan with about 1 tbsp of olive oil. Place the salmon fillets into the hot pan and cook for about 3-4 minutes, then flip and cook for an additional 4 minutes until the salmon is cooked to your liking. Alternatively, you can bake or air-fry the salmon on 375 F for 8-10 minutes, then broil for 1-2 minutes at the end.
Prepare the lemon vinaigrette by whisking together the dressing ingredients until smooth.
Serve the salmon over the chopped salad topped with the vinaigrette and sumac onions with a side of the pita chips and hummus