Adjust rack to top position (top and middle positions for 4 servings) and preheat oven to 425 degrees. Wash and dry produce.

Cut sweet potatoes into ½-inch-thick wedges. Trim and thinly slice scallions, separating whites from greens. Finely chop cilantro. Trim cucumber. Using a peeler, shave cucumber lengthwise into ribbons, rotating as you go, until you get to the seedy core; discard core.

On one side of a baking sheet, toss sweet potatoes with a large drizzle of oil, Za'atar Spice, salt, and pepper. (For 4, spread sweet potatoes out across entire sheet.) Set aside (you'll add more to the sheet later).

Drain and rinse chickpeas; pat dry with paper towels.

Place chickpeas and 1 tsp olive oil (2 tsp for 4 servings) in a large bowl. Using an immersion blender, blend until almost smooth (it’s OK if there are still some chunks of chickpeas). TIP: If you don't have an immersion blender, use a standard blender or a food processor!

To bowl with chickpeas, mix in scallion whites, cilantro, Turkish Spice Blend, and flour. Taste and season with salt (we used ½ tsp; 1 tsp for 4 servings) and pepper.

Divide chickpea mixture into two mounds (four mounds for 4 servings); gently flatten into patties (ours were 2-3 inches wide).

Lightly drizzle oil on empty side of baking sheet with sweet potatoes; add patties. Bake on top rack for 10 minutes. (For 4 servings, add patties to a second sheet; bake patties on top rack and sweet potatoes on middle rack.)

Carefully flip patties and return to top rack until patties are lightly golden and sweet potatoes are browned and tender, 10-12 minutes more.

While patties and sweet potatoes bake, halve and toast buns until golden.

In a small bowl, combine cucumber, scallion greens, a drizzle of olive oil, a pinch of salt, and pepper.

Fill buns with patties, tzatziki, and cucumber ribbons.

Divide burgers and sweet potato wedges between plates and serve.