In a small dry pan over medium heat, toast the coriander seeds and cumin seeds for 2-3 minutes, stirring occasionally, until fragrant. Transfer to a mortar and pestle and crush the coriander seeds (leave cumin seeds mostly whole for texture). In a separate small bowl, mince the garlic and mix with the Aleppo pepper—this aromatics mixture will bloom when the hot oil hits it. Heat the olive oil in a small saucepan over medium heat for about 2 minutes until shimmering, then add the toasted spices and cook for another 2 minutes to infuse the oil. Pour the hot oil mixture directly over the garlic-pepper mixture and let it sit for 1 minute to bloom the aromatics and develop deeper flavor. I find this technique creates a more vibrant spice flavor than if you just mixed everything cold.
In a medium bowl, combine the tahini, ice water, lemon juice, maple syrup, and salt. Whisk vigorously for 1-2 minutes until the mixture becomes light, creamy, and slightly fluffy—the ice water is key here as it aerates the tahini and creates a silky consistency rather than a thick paste. Set aside until ready to plate. I like to make this dressing while the spiced oil is cooling slightly so everything comes together at the right time.
While the dressing is setting, drain and rinse the chickpeas if using canned, then transfer them to a large bowl. Pour the spiced oil mixture from Step 1 over the chickpeas and stir well. Add the finely minced preserved lemon peel, lemon juice, sumac, nutritional yeast, and salt to the chickpeas, stirring to coat everything evenly—the chickpeas will absorb these flavors as they sit. In a separate bowl, dice the red onion into 1/4-inch pieces and soak them in ice water for 10 minutes, then drain thoroughly; this mellows the raw onion bite while keeping it crisp. Slice the Persian cucumbers into 1/2-inch half-moons and have them ready. Roughly chop the parsley, mint, and cilantro, keeping them separate or divided in half so you can reserve some for garnish.
Add the drained red onion, sliced cucumbers, sesame seeds, and half of the chopped herbs (reserve the remaining herbs for garnish) to the seasoned chickpeas from Step 3, then toss gently to combine—be careful not to crush the chickpeas. Taste and adjust seasoning if needed. Spread a generous layer of the tahini dressing from Step 2 across serving plates or a large platter, creating a smooth base. Top with the chickpea salad mixture, allowing some of the beautiful dressed chickpeas and vegetables to peek through the creamy tahini. Finish with the reserved fresh herbs scattered over the top and a light sprinkle of Maldon flaky salt for that final crunch and visual appeal.