Heat olive oil in a wide lidded non-stick cooking pan/sauté pan/dutch oven on medium. Add nigella seeds, cumin seeds, bay leaves, chilli, garlic and ginger. Sauté for a few seconds till the seeds start crackling. Add onion and cook tossing constantly until onions are caramelized.
Add potatoes, cauliflower and salt. Cook tossing constantly for 8-10 minutes until both potato and cauliflower are golden and starting to brown.
Add tomato, turmeric, coriander, garam masala, chat masala and kasoori methi. Mix well.
Reduce heat to medium-low, add water, cover and cook on that slow heat for 15-20 minutes until the potatoes are cooked through. Check often and toss gently to ensure even cooking and avoiding the veggies from sticking and burning. If too dry, add another tablespoon of water. Check and add a bit more salt if required.
Remove from heat, garnish with chopped coriander and serve hot with lemon wedges alongside rotis or rice.
* Red Cayenne chilli is a thick long chilli with mild to medium heat. If you prefer your curry to not have this spice, just skip it or add only a couple of slices of the chilli.**Chat Masala or Amchur (Dry mango powder) can be found at Indian grocers or specialty spice shops. If you can't find these spices, just squeeze half a lemon to add the sour element.***Kasoori methi is dried Fenugreek leaves. It has a bitter earthy flavour that imparts a delicious warmth and richness to this curry. You can also source this at Indian grocers or specialty spice stores.