Begin by cooking the orzo according to the package directions in salted water. When cooked to al dente, drain well and rinse briefly with cold water. Meanwhile, in a small bowl, combine minced shallot, zest, and juice of one lemon, white wine vinegar, and 1 ½ tsp salt. Let sit for 5-10 minutes to quick pickle the shallot. In a large bowl, combine olive oil, tahini, and harissa. Stir in shallot, lemon and vinegar mixture along with the drained chickpeas. Then, mix in cooked orzo, parsley, capers, cucumbers, and tomatoes. Top with a bit of freshly ground black pepper and season with salt to taste if desired.