Step 1: Preheat your oven to 400°F (200°C). On a large baking sheet, toss the cauliflower florets and pumpkin cubes with 2 tablespoons of olive oil, turmeric, salt, and pepper. Spread in a single layer and roast for 25-30 minutes until tender and caramelized with charred edges.
Step 2: While vegetables roast, heat the remaining 1 tablespoon of oil in a large pot over medium heat. Add the onion and sauté for 5-7 minutes until soft. Stir in the garlic and ginger, cooking for another 1 minute until fragrant.
Step 3: Add the curry paste to the pot and stir constantly for 2 minutes to toast the spices. Slowly pour in the coconut milk, vegetable broth, and maple syrup. Bring to a gentle simmer.
Step 4: Once the roasted vegetables are ready, carefully stir them into the coconut sauce. Let the roasted cauliflower and pumpkin curry simmer together for 5-10 minutes to allow flavors to meld.
Step 5: Stir in the lime juice and adjust seasoning with extra salt if needed. Serve hot over rice, garnished with fresh cilantro.