Roast the vegetables: Preheat the oven to 425°F with a rack in the middle.

Put the eggplant and red onion on a large sheet pan.

Drizzle 2 tablespoons of the olive oil over the vegetables. Sprinkle on the za'atar and 1/2 teaspoon of the salt, then toss well and spread everything into one layer.

Roast the sheet pan for 15 minutes.

Take the pan out, stir the vegetables, and spread them back out. Return the pan to the oven and roast for 10 to 15 minutes more, until the eggplant is very tender and browned at the edges and the onion has dark spots.

Cook the bulgur: While the vegetables roast, pour 1 1/2 cups water into a medium saucepan and bring it to a boil over high heat.

Add the bulgur to the boiling water with 1/4 teaspoon of the salt. Stir once, cover the saucepan, remove it from the heat, and let it stand for 12 minutes.

Warm the beans: Put the kidney beans, the remaining 1 tablespoon olive oil, the cumin, 1/4 cup water, and the remaining 1/4 teaspoon salt in a small skillet. Set the skillet over medium heat.

Cook the beans for 4 to 5 minutes, stirring now and then, until they are hot all the way through.

Press some of the beans lightly with the back of a spoon in the skillet. Cook 1 minute more, until the liquid looks a little thicker and coats the beans.

Make the yogurt and toppings: Put the Greek yogurt in a small bowl. Stir in the juice from half of the lemon and a small pinch of salt until smooth.

Put the diced cucumber and chopped parsley on a plate or in a small bowl so they are ready to use. Keep the remaining lemon wedges for serving.