Accidentally Vegan: Cauliflower, Potato, and Chickpea Curry

Please excuse the crappy picture on this one, I swear, I took it with my real camera, not my iPhone. I think my food picture taking skills need some improvement. Maybe I need one of those cameras with a food setting :) Poor photography notwithstanding, this dish and simple, scrumptious, and a little spicy (I like alliteration). And as a bonus, I realized after we ate it that it is vegan (which is exciting to me because I always like to have some tricks up my sleeve in case a vegan friend comes to visit)!

Cauliflower, Potato, and Chickpea Curry
Adapted from Cooks Illustrated

Ingredients
1 tablespoon garam masala
1 teaspoon cumin
1 teaspoon coriander
1/4 teaspoon tumeric
1/4 cup vegetable oil
2 medium onions , chopped fine (about 2 cups)
12 ounces potatoes , scrubbed and cut into 1/2-inch pieces (about 2 cups)
3 medium cloves garlic , minced (about 1 tablespoon)
1 tablespoon finely grated fresh ginger (when we buy fresh ginger, we peel it, cut it into small chunks, and freeze it to use later)
1 - 1 1/2 serrano chiles , ribs, seeds, and flesh minced
1 tablespoon tomato paste
1/2 medium head cauliflower
1 can (14 1/2 ounces) diced tomatoes , pulsed in food processor  until nearly smooth with 1/4-inch pieces visible
1 1/4 cups water
1 (15 ounce) can chickpeas , drained and rinsed
Table salt
1/4 cup coconut milk

Instructions

1. Adjust oven rack to lowest position and heat oven to 475 degrees. Trim outer leaves of cauliflower and cut stem flush with bottom. Cut head into 8 equal wedges so that core and florets remain intact. Place wedges cut side down on foil- or parchment-lined rimmed baking sheet. Drizzle with 2 tablespoons oil and sprinkle with salt and pepper; gently rub to evenly distribute oil and seasonings. Gently flip cauliflower and season other cut side with remaining 2 tablespoons oil, salt, and pepper.
2. Cover baking sheet tightly with foil and cook for 10 minutes. Remove foil and continue to roast until bottoms of cauliflower pieces are golden, 8 to 12 minutes. Remove sheet from oven, and, using spatula, carefully flip wedges. Return sheet to oven and continue to roast until cauliflower is golden all over, 8 to 12 minutes longer. 
3. Toast spices in small skillet over medium-high heat, stirring constantly, until they darken slightly and become fragrant, about 1 minute. Remove spices from skillet and set aside.
4. Heat 3 tablespoons oil in large dutch oven over medium-high heat until shimmering. Add onions and potatoes and cook, stirring occasionally, until onions are caramelized and potatoes are golden brown on edges, about 10 minutes. (Reduce heat to medium if onions darken too quickly.)
5. Reduce heat to medium. Clear center of pan and add remaining tablespoon oil, garlic, ginger, chile, and tomato paste; cook, stirring constantly, until fragrant, about 30 seconds. Add toasted spices and cook, stirring constantly, about 1 minute longer. Add cauliflower and cook, stirring constantly, until spices coat florets, about 2 minutes longer.
6. Add tomatoes, water, chickpeas, and 1 teaspoon salt; increase heat to medium-high and bring mixture to boil, scraping bottom of pan with wooden spoon to loosen browned bits. Cover and reduce heat to medium. Simmer briskly, stirring occasionally, until vegetables are tender, 10 to 15 minutes. Stir in coconut milk; continue to cook until heated through, about 2 minutes longer. Adjust seasoning with salt and serve immediately over brown rice.