Wash and dry all produce. Adjust rack to upper position and preheat oven to 425 degrees. Cut cauliflower into 1/2-inch pieces. Zest lemon, then cut into quarters. Peel ginger, then mince or grate.

Toss squash and cauliflower on a baking sheet with a large drizzle of olive oil, 2 tsp curry powder (save the rest for step 4), coriander, salt, and pepper. Roast in oven until tender and lightly browned, 20-25 minutes.

Meanwhile, heat a drizzle of olive oil in a medium pot over medium-high heat. Add ginger. Cook until fragrant, about 30 seconds. Add rice and 3/4 cup water. Bring to a boil, then cover, lower heat, and reduce to a gentle simmer. Cook until tender, 12-15 minutes. Keep covered off heat.

Place sour cream in a small bowl, then squeeze in juice from 1 lemon quarter. Stir in 1 TBSP water, a drizzle of olive oil, and a pinch of curry powder. Season with salt.

Fluff rice with a fork, then stir in lemon zest.

Divide rice between plates. Top with roasted squash and cauliflower. Drizzle with crema. Serve with remaining lemon quarters for squeezing over.