Preheat oven to 230°C (or 210°C fan bake).
Prep cauliflower and toss on a lined oven tray with oil, cauliflower spices and salt. Roast on upper oven rack for 15-20 minutes, until golden and tender.
Prep onion and lentils. Heat oil in a medium fry-pan on medium-high heat. Cook onion for 3-4 minutes, until browned. Add lentil spices, lentils and a pinch of salt to pan and cook for 3-4 minutes, until lentils have browned. Add tamarind sauce to pan and cook for a further minute, until mixture is golden and sticky. Season to taste with salt and pepper.
Wrap tortillas in foil and heat on lower oven rack for 12-14 minutes, until warmed through. Alternatively, wrap tortillas in a damp tea towel and heat in microwave for 1-2 minutes, until warm.
Prep tomato, apple and lime and toss in a bowl with peanuts, olive oil and a pinch of salt. Set aside.
In a small bowl, mix mayo, lime juice and beetroot powder together (if using). Prep mint.
Serve tortillas filled with lentils, cauliflower, salsa, rocket, beetroot mayo and mint.