Preheat the oven to 200°C (convection). Line a baking sheet with baking paper.
Prepare the cauliflower: Wash the cauliflower and cut into bite-sized florets (approximately 3-4 cm). Place in a large bowl, drizzle with 2 tbsp olive oil, and sprinkle with smoked paprika, cumin, turmeric, salt, and pepper. Toss until evenly coated. Spread florets in a single layer on the baking sheet.
Roast the cauliflower for 30–35 minutes, flipping halfway through, until golden brown and crispy at the edges.
Start the pilaf: While cauliflower roasts, peel and finely dice the onion. Peel and mince the garlic using a garlic press. Heat 1 tbsp olive oil in a pot over medium heat. Sauté the onion for 4–5 minutes until softened and lightly golden.
Add aromatics and grains: Add garlic, cinnamon, and allspice to the onion. Stir for 30 seconds until fragrant. Add the rinsed red lentils and basmati rice, stir to coat in the spices.
Cook the pilaf: Pour in the vegetable broth, bring to a boil, then reduce heat to low. Cover with a lid and simmer for 15–18 minutes until the liquid is absorbed and lentils/rice are tender. Remove from heat and let rest covered for 5 minutes. Fluff with a fork.
Make the tahini drizzle: In a small bowl, whisk together tahini, lemon juice, maple syrup, and sumac. Add warm water gradually, whisking until you reach a pourable consistency. Season with a pinch of salt.
Toast the pine nuts: In a dry pan over medium-low heat, toast the pine nuts for 2–3 minutes, stirring frequently, until golden. Set aside.
Assemble: Divide the pilaf among 3 plates or shallow bowls. Top with roasted cauliflower florets. Drizzle generously with the sumac-tahini sauce. Garnish with pomegranate seeds, toasted pine nuts, and fresh parsley.