Press the tofu for at least 20–30 minutes to remove excess moisture. Once pressed, cut it into bite-sized cubes.
In a small pan, warm the oil over medium heat. Add the tandoori masala blend, turmeric, and paprika. Stir continuously for about 20–30 seconds until fragrant. This quick bloom helps wake up the spices and deepens the flavour of the marinade.
Transfer the bloomed spices and oil to a large mixing bowl. Add the vegan sour cream or yogurt, garlic, ginger, lemon juice, maple syrup, chickpea flour, salt, and chili flakes. Whisk until smooth and fully combined.
Add the cubed tofu, bell peppers, and onion to the bowl. Gently toss everything until evenly coated. Allow to marinate for at least 30 minutes, or up to 4 hours for maximum flavour.
Preheat the oven to 425°F (220°C). Line a baking sheet with parchment paper and spread the tofu and vegetables into an even layer. Roast on the middle rack for 30–35 minutes, tossing halfway through cooking.
For extra charred, restaurant-style edges, place the tray under the broiler for 2–3 minutes at the end of cooking. Keep a close eye on it—those gorgeous crispy edges appear quickly.