Preheat oven to 425°F (220°C). Dry chickpeas thoroughly with a kitchen towel. Toss with olive oil and all spices. Spread in a single layer on a parchment-lined baking sheet. Roast for 20 to 25 minutes, shaking halfway, until deeply golden and crispy.
Whisk tahini, lemon juice, lemon zest, garlic, salt, and cumin together. Add warm water one tablespoon at a time, whisking until smooth and pourable. Drizzle with olive oil. Taste and adjust.
Fluff cooked rice with a fork. Fold in olive oil, lemon juice, chopped herbs, and a pinch of salt.
Dice cucumber, halve tomatoes, halve olives. Prepare pickled onion or soak fresh red onion in cold water for 5 minutes.
Divide herbed rice between four bowls. Arrange crispy chickpeas over one section. Place fresh toppings in separate sections around the bowl. Crumble feta and scatter parsley and pine nuts over the top.
Drizzle lemon tahini sauce generously over each bowl. Serve immediately with extra sauce on the side.