Heat a nice healthy layer of olive oil in a skillet over medium heat.
When the oil is shimmering, add the torn bagel pieces to the skillet and heat, stirring occasionally, until they're hot and crispy and golden brown on the outside.
In a medium bowl, toss together the cucumber, onion, and lemon.
Spread the yogurt between two shallow bowls.
Top each with a handful of greens, half of the cucumber mixture, a drizzle of olive oil, a good pinch of salt, a few turns of pepper, a dusting of sumac, half of the fried bagel, and a good drizzle of tahini sauce.
Top it with chickpeas or an egg, if using, and then finish it off with the fresh herbs.
