Marinate onions by combining sliced red onions with olive oil, sumac, Aleppo pepper, and salt in a medium bowl. Let it marinate for at least 30 minutes.

Prepare couscous by boiling water in a saucepan. Stir in couscous, reduce heat, cover, and cook for about 10 minutes. Fluff with a fork once done.

Chop arugula and spinach, adding to a large bowl, then top with sliced cucumber.

Cook halloumi by soaking slices in lemon juice and hot honey mixture for 5 minutes, then sear in a skillet for 2-3 minutes on each side until golden brown.

Make the dressing by whisking parsley, olive oil, remaining lemon juice, salt, and water until well blended.

Assemble the salad by adding couscous and marinated onions to the greens and cucumber. Top with crispy halloumi and drizzle the dressing over the salad.