Prepare the tofu: Cut the firm tofu into 1cm (0.4 inch) cubes and place in a bowl. Add tamari or soy sauce and oil, then mix well to coat evenly.
Bake the tofu: Preheat the oven or air fryer to 200°C (392°F). Spread the tofu evenly on a baking tray and bake for 15–20 minutes, stirring once or twice, until golden brown.
Blend the sauce: In a blender or food processor, add fresh ginger, garlic, baby spinach or greens, vegetable stock, lemon juice, cumin seeds, garam masala, curry powder, tamari or soy sauce, maple syrup, salt, and black pepper. Blend until smooth.
Cook the base: Heat a frying pan over high heat. Once hot, add oil followed by the finely sliced red onion. Fry for 3–4 minutes, stirring occasionally until softened.
Combine and cook: Add the baked tofu and blended sauce to the pan. Cook for 3–4 minutes, stirring occasionally, until the sauce thickens. Taste and adjust seasoning by adding more salt, lemon juice, or sweetener if needed.
Serve: Plate up the curry with freshly cooked rice and a side of red sauerkraut for a delicious and healthy meal!