Preheat oven to 425°F.
Add potatoes, chickpeas, and cauliflower to a large rimmed baking sheet (18" x 13"). Make sure there is roughly ¼ to ½ inches between pieces for even roasting. If desired, keep ingredients separated by type.
Drizzle with olive oil, then sprinkle with 1 teaspoon of curry powder, 1 teaspoon of garam masala, and salt & pepper to taste over the potatoes, chickpeas and cauliflower. Toss lightly to evenly coat.
Roast in preheated oven for 15 minutes, remove and toss.
In a second large rimmed baking sheet, evenly spread kale and onions and toss with remaining 1 teaspoon of curry powder, 1 teaspoon of garam masala and salt & pepper to taste.
Once the potatoes, cauliflower, and chickpeas have been baking for 15 minutes, place the kale and onions into the oven. Roast both pans for an additional 15 minutes.
Meanwhile, make tahini sauce: In a bowl, combine tahini, yogurt, sugar/honey, garlic, ½ of the lemon juice, lemon zest, salt & pepper, and 2 teaspoons of water. Mix until smooth and creamy. If too thick, add more water to thing. Taste and add more lemon juice if needed.
To assemble bowls, layer with potatoes, followed by kale and onions, chickpeas, and cauliflower. Drizzle with tahini sauce and parsley.