Make the roasted chickpeas: Preheat the oven to 425°F and line a baking sheet with heavy-duty aluminum foil. Place the chickpeas on the prepared baking sheet and toss with the olive oil, salt, pepper, and cumin. Roast for 20 to 25 minutes, stirring once, until the chickpeas are golden and crispy. Let cool.

Meanwhile, make the yogurt sauce: In a small bowl, whisk together the yogurt, mayonnaise, lemon juice, garlic, dill, and salt. Taste and adjust seasoning, if necessary.

Make the tomato-cucumber salad: In a medium bowl, toss together the parsley, tomatoes, cucumber, scallions, salt, oil, and lemon juice.

To serve: Spread the hummus on a serving platter, using the back of a spoon to swirl it nicely. Spoon three-quarters of the tomato-cucumber salad (including the juices) over the hummus. Scatter the roasted chickpeas over the salad and dollop the yogurt sauce around the top (you may not need all of it). Spoon the remaining salad over top. Serve with pita wedges or pita chips.

The hummus and yogurt sauce can be made up to 3 days ahead of time and stored in the refrigerator. The salad can be prepared up to 3 hours ahead of time and stored in the fridge. The chickpeas are best made before serving, but they can be prepared up to 3 hours ahead and stored at room temperature; if necessary, you can crisp them back up by reheating in a 350°F-oven until hot. The hummus board is best assembled right before serving.