Preheat your oven to 400°F.
Chop all the vegetables into 1-inch pieces for even roasting.
In a large bowl, combine the chopped veggies with a drizzle of olive oil, tossing to coat evenly.
Squeeze the juice of one lemon over the veggies.
Sprinkle a tablespoon of sumac, a pinch of salt, and a sprinkle of black pepper over the mixture, tossing again to distribute the spices.
Spread the veggies in a single layer on a baking sheet to ensure they crisp up nicely.
Roast in the preheated oven for 25-30 minutes, or until the edges are golden brown and crispy.
Remove from the oven and let cool for 2-3 minutes before serving.
