Preheat the oven to 425°F and line a large, rimmed baking sheet pan with parchment paper or greased foil if broiling.
In a small bowl, combine all the seasonings (za’atar, cumin, salt, and pepper). Toss the carrots with oil and seasoning. (Tip: I do this right on the baking sheet, but you can use a bowl if you prefer. I also use my hands to rub the spices over the carrots, helping to evenly distribute them.)
Arrange the carrots in a single layer on the baking sheet, and bake for about 15 minutes, depending on thickness of the carrots and preferred level of doneness. Start checking after about 12-13 minutes. I like the carrots to be tender with a hint of resistance when pierced with the tip of a sharp knife.
If using feta, you can sprinkle it over the cooked carrots. Or for a hint of char on the top of the carrots and feta, set the oven to broil, push the carrots together on the baking sheet, and then sprinkle with the feta. Broil on the top rack, watching very closely, for a minute or two or until golden brown in spots.
Serve warm, with optional herb or garnish of choice, if desired.
Storage: Cooked carrots will keep for up to 5 days in the refrigerator.