Preheat the oven to 400ºF. On a rimmed baking sheet, toss sweet potatoes and onions with just enough olive oil to coat, season with salt and pepper, and arrange in a single layer. Transfer to the oven and roast 45 minutes - 1 hour, tossing every 15 minutes or so, until the sweet potatoes are soft and beginning to brown.
Meanwhile, bring 2 cups of water to a boil in a medium saucepan. Add the bulgur and stir once, then cover and reduce heat to low. Allow to cook without disturbing until all the water has been absorbed, 15-20 minutes. Once done, turn off the heat, fluff the bulgur, and allow to sit, covered, for at least five minutes while you get everything else ready.
While the bulgur is cooking, make the roasted chickpeas and chop any vegetables. When the chickpeas come out of the oven, add dried oregano to the pan and stir to coat.
To assemble the bowls, add a scoop of bulgur and top with sweet potatoes, onions, tomatoes, red peppers, olives, crumbled feta, chopped parsley, roasted chickpeas, and a good squeeze of lemon juice.